Use a floating-point number for the `timeout` property in HTTPRequest

This allows for greater precision when specifying a timeout in
HTTPRequest in `3.x`, similar to what is already possible in `master`.

doc/classes/HTTPRequest.xml

@@ -142,19 +142,21 @@
 	</methods>
 	<members>
 		<member name="body_size_limit" type="int" setter="set_body_size_limit" getter="get_body_size_limit" default="-1">
-			Maximum allowed size for response bodies.
+			Maximum allowed size for response bodies ([code]-1[/code] means no limit). When only small files are expected, this can be used to prevent disallow receiving files that are too large, preventing potential denial of service attacks.
 		</member>
 		<member name="download_chunk_size" type="int" setter="set_download_chunk_size" getter="get_download_chunk_size" default="65536">
 			The size of the buffer used and maximum bytes to read per iteration. See [member HTTPClient.read_chunk_size].
 			Set this to a lower value (e.g. 4096 for 4 KiB) when downloading small files to decrease memory usage at the cost of download speeds.
 		</member>
 		<member name="download_file" type="String" setter="set_download_file" getter="get_download_file" default="&quot;&quot;">
-			The file to download into. Will output any received file into it.
+			The file to download into. If set to a non-empty string, the request output will be written to the file located at the path. If a file already exists at the specified location, it will be overwritten as soon as body data begins to be received.
+			[b]Note:[/b] Folders are not automatically created when the file is created. If [member download_file] points to a subfolder, it's recommended to create the necessary folders beforehand using [method Directory.make_dir_recursive] to ensure the file can be written.
 		</member>
 		<member name="max_redirects" type="int" setter="set_max_redirects" getter="get_max_redirects" default="8">
-			Maximum number of allowed redirects.
+			Maximum number of allowed redirects. This is used to prevent endless redirect loops.
 		</member>
-		<member name="timeout" type="int" setter="set_timeout" getter="get_timeout" default="0">
+		<member name="timeout" type="float" setter="set_timeout" getter="get_timeout" default="0.0">
+			If set to a value greater than [code]0.0[/code], the HTTP request will time out after [code]timeout[/code] seconds have passed and the request is not [i]completed[/i] yet. For small HTTP requests such as REST API usage, set [member timeout] to a value greater than [code]0.0[/code] to prevent the application from getting stuck if the request fails to get a response in a timely manner. For file downloads, leave this to [code]0.0[/code] to prevent the download from failing if it takes too much time.
 		</member>
 		<member name="use_threads" type="bool" setter="set_use_threads" getter="is_using_threads" default="false">
 			If [code]true[/code], multithreading is used to improve performance.

scene/main/http_request.cpp

@@ -81,7 +81,7 @@ Error HTTPRequest::request_raw(const String &p_url, const Vector<String> &p_cust
 	ERR_FAIL_COND_V(!is_inside_tree(), ERR_UNCONFIGURED);
 	ERR_FAIL_COND_V_MSG(requesting, ERR_BUSY, "HTTPRequest is processing a request. Wait for completion or cancel it before attempting a new one.");
 
-	if (timeout > 0) {
+	if (timeout > 0.0) {
 		timer->stop();
 		timer->start(timeout);
 	}
@@ -471,12 +471,16 @@ void HTTPRequest::set_https_proxy(const String &p_host, int p_port) {
 	client->set_https_proxy(p_host, p_port);
 }
 
-void HTTPRequest::set_timeout(int p_timeout) {
-	ERR_FAIL_COND(p_timeout < 0);
-	timeout = p_timeout;
+void HTTPRequest::set_timeout(double p_timeout) {
+	if (Math::is_zero_approx(p_timeout)) {
+		timeout = 0.0;
+	} else {
+		ERR_FAIL_COND(p_timeout < 0.0);
+		timeout = p_timeout;
+	}
 }
 
-int HTTPRequest::get_timeout() {
+double HTTPRequest::get_timeout() {
 	return timeout;
 }
 
@@ -526,7 +530,7 @@ void HTTPRequest::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "use_threads"), "set_use_threads", "is_using_threads");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "body_size_limit", PROPERTY_HINT_RANGE, "-1,2000000000"), "set_body_size_limit", "get_body_size_limit");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "max_redirects", PROPERTY_HINT_RANGE, "-1,64"), "set_max_redirects", "get_max_redirects");
-	ADD_PROPERTY(PropertyInfo(Variant::INT, "timeout", PROPERTY_HINT_RANGE, "0,86400"), "set_timeout", "get_timeout");
+	ADD_PROPERTY(PropertyInfo(Variant::REAL, "timeout", PROPERTY_HINT_RANGE, "0,3600,0.1,or_greater"), "set_timeout", "get_timeout");
 
 	ADD_SIGNAL(MethodInfo("request_completed", PropertyInfo(Variant::INT, "result"), PropertyInfo(Variant::INT, "response_code"), PropertyInfo(Variant::POOL_STRING_ARRAY, "headers"), PropertyInfo(Variant::POOL_BYTE_ARRAY, "body")));
 
@@ -565,7 +569,7 @@ HTTPRequest::HTTPRequest() {
 	timer->set_one_shot(true);
 	timer->connect("timeout", this, "_timeout");
 	add_child(timer);
-	timeout = 0;
+	timeout = 0.0;
 }
 
 HTTPRequest::~HTTPRequest() {

scene/main/http_request.h

@@ -94,7 +94,7 @@ private:
 
 	int max_redirects;
 
-	int timeout;
+	double timeout;
 
 	void _redirect_request(const String &p_new_url);
 
@@ -138,8 +138,8 @@ public:
 
 	Timer *timer;
 
-	void set_timeout(int p_timeout);
-	int get_timeout();
+	void set_timeout(double p_timeout);
+	double get_timeout();
 
 	void _timeout();