Feature: Toggle Explorer Arrows Configuration

[barelyhuman]

• register command to handle arrow toggling, removed since it adds a lot of complexity to a simple change which can be a lot easily handled by just changing the configuration
• split up into maintainable modules
• move .json to .default.json for the default settings and generate a new .json from it when the theme is first activated , added an ignored file .modified.json that vscode will look for so the source stays as is
• add a listener for configuration changes to make this portable

Adds to the vscode configuration

"symbols.hidesExplorerArrows":true

[barelyhuman]

The force-push only edits one commit 0c6c832, since changes were added to main yesterday that weren't in the fork and the mentioned commit removed trailing commas in the JSON

Hope that's fine :)

[miguelsolorio]

This is a huge PR, thank you so much for tackling this! Made some minor changes and show a notification when the change has been made to ask users to reload.

EDIT: Ended up removing the notification as it was unnecessary.

[miguelsolorio]

@barelyhuman one issue I am seeing is that if symbol-icon-theme.modified.json already exists, when you make changes to symbol-icon-theme.json the modified file does not get updated. It's almost like we need to do cleanup when activating the extension. Would you be able to add this?

[barelyhuman]

i guess I totally forgot about handling updates in the theme, will add a sync on activation to check for new props.

Should be able to raise a PR around noon tomorrow