Adds a TabOut functionality inspired by the fantastic Visual Studio Code plugin by Albert Romkes.

If your blinking typing indicator (called the caret) is to the left of a closing bracket/parenthesis/quote, pressing tab will move the carat one character to the right, jumping out without needing to move you right hand to the arrow keys!

It also adds the reverse "TabIn" on shift + tab allowing you to jump back into the String or function from the outside.

It's designed to not affect Godot's default tab and shift + tab behaviour where it shouldn't; indenting highlighted code and indenting normally with tab still work as expected.

Technical details for those interested:

It's implemented as a tool script that hooks into the editors current CodeEdit node and overrides its gui_input signal. It checks whether the tab/shift+tab should be interpreted as a tabout, if so it calls the viewport's set_input_as_handled(), if not it just returns and lets the event propagate down the tree until its caught for default indentation logic. At the moment it only looks ahead or behind one character for simplicity.