Rename str2var to str_to_var and similar

Affects the Math class, a good chunk of the audio code, and a lot of other miscellaneous classes, too.

- `var2str` -> `var_to_str`
- `str2var` -> `str_to_var`
- `bytes2var` -> `bytes_to_var`
- `bytes2var_with_objects` -> `bytes_to_var_with_objects`
- `var2bytes` -> `var_to_bytes`
- `var2bytes_with_objects` -> `var_to_bytes_with_objects`
- `linear2db` -> `linear_to_db`
- `db2linear` -> `db_to_linear`
- `deg2rad` -> `deg_to_rad`
- `rad2deg` -> `rad_to_deg`

- `dict2inst` -> `dict_to_inst`
- `inst2dict` -> `inst_to_dict`

editor/import/collada.cpp

@@ -131,7 +131,7 @@ Transform3D Collada::Node::compute_transform(const Collada &state) const {
 		switch (xf.op) {
 			case XForm::OP_ROTATE: {
 				if (xf.data.size() >= 4) {
-					xform_step.rotate(Vector3(xf.data[0], xf.data[1], xf.data[2]), Math::deg2rad(xf.data[3]));
+					xform_step.rotate(Vector3(xf.data[0], xf.data[1], xf.data[2]), Math::deg_to_rad(xf.data[3]));
 				}
 			} break;
 			case XForm::OP_SCALE: {

editor/import/post_import_plugin_skeleton_rest_fixer.cpp

@@ -324,7 +324,7 @@ void PostImportPluginSkeletonRestFixer::internal_process(InternalImportCategory
 				Vector3 src_dir = src_tail - src_head;
 
 				// Rotate rest.
-				if (Math::abs(Math::rad2deg(src_dir.angle_to(prof_dir))) > float(p_options["retarget/rest_fixer/fix_silhouette/threshold"])) {
+				if (Math::abs(Math::rad_to_deg(src_dir.angle_to(prof_dir))) > float(p_options["retarget/rest_fixer/fix_silhouette/threshold"])) {
 					// Get rotation difference.
 					Vector3 up_vec; // Need to rotate other than roll axis.
 					switch (Vector3(abs(src_dir.x), abs(src_dir.y), abs(src_dir.z)).min_axis_index()) {

editor/import/resource_importer_wav.cpp

@@ -390,7 +390,7 @@ Error ResourceImporterWAV::import(const String &p_source_file, const String &p_s
 		int first = 0;
 		int last = (frames / format_channels) - 1;
 		bool found = false;
-		float limit = Math::db2linear(TRIM_DB_LIMIT);
+		float limit = Math::db_to_linear(TRIM_DB_LIMIT);
 
 		for (int i = 0; i < data.size() / format_channels; i++) {
 			float ampChannelSum = 0;