Allow `size` values as low as `0.001` in Camera's orthogonal/frustum mode

This allows for lower field of view (or higher zoom) in orthogonal
and frustum camera modes.

The property hint also allows setting the size with greater precision.

doc/classes/Camera.xml

@@ -177,7 +177,7 @@
 			The camera's projection mode. In [constant PROJECTION_PERSPECTIVE] mode, objects' Z distance from the camera's local space scales their perceived size.
 		</member>
 		<member name="size" type="float" setter="set_size" getter="get_size" default="1.0">
-			The camera's size measured as 1/2 the width or height. Only applicable in orthogonal mode. Since [member keep_aspect] locks on axis, [code]size[/code] sets the other axis' size length.
+			The camera's size measured as 1/2 the width or height. Only applicable in orthogonal and frustum modes. Since [member keep_aspect] locks on axis, [code]size[/code] sets the other axis' size length.
 		</member>
 		<member name="v_offset" type="float" setter="set_v_offset" getter="get_v_offset" default="0.0">
 			The vertical (Y) offset of the camera viewport.

scene/3d/camera.cpp

@@ -525,7 +525,7 @@ void Camera::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "projection", PROPERTY_HINT_ENUM, "Perspective,Orthogonal,Frustum"), "set_projection", "get_projection");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "current"), "set_current", "is_current");
 	ADD_PROPERTY(PropertyInfo(Variant::REAL, "fov", PROPERTY_HINT_RANGE, "1,179,0.1"), "set_fov", "get_fov");
-	ADD_PROPERTY(PropertyInfo(Variant::REAL, "size", PROPERTY_HINT_RANGE, "0.1,16384,0.01"), "set_size", "get_size");
+	ADD_PROPERTY(PropertyInfo(Variant::REAL, "size", PROPERTY_HINT_RANGE, "0.001,16384,0.001"), "set_size", "get_size");
 	ADD_PROPERTY(PropertyInfo(Variant::VECTOR2, "frustum_offset"), "set_frustum_offset", "get_frustum_offset");
 	ADD_PROPERTY(PropertyInfo(Variant::REAL, "near", PROPERTY_HINT_EXP_RANGE, "0.01,8192,0.01,or_greater"), "set_znear", "get_znear");
 	ADD_PROPERTY(PropertyInfo(Variant::REAL, "far", PROPERTY_HINT_EXP_RANGE, "0.1,8192,0.1,or_greater"), "set_zfar", "get_zfar");
@@ -574,7 +574,7 @@ void Camera::set_fov(float p_fov) {
 }
 
 void Camera::set_size(float p_size) {
-	ERR_FAIL_COND(p_size < 0.1 || p_size > 16384);
+	ERR_FAIL_COND(p_size < 0.001 || p_size > 16384);
 	size = p_size;
 	_update_camera_mode();
 	_change_notify("size");