Add one click format button

[maizehsu]

TL;DR

Add a one click format button to the main editor.

What changed?

• Add a utility function that formats file content based on file type.
• Add a button UI in Toolbar that controls the formatting of the file content.

How to test?

Open a file under JSON, YAML or XML format and click format to see the change. Other file formats should stay the same after formatting.

JSON before format:

JSON after format:

YAML before format:

YAML after format:

XML before format:

XML after format:

Why make this change?

One click format or in the future configurable format on save could be a really handy feature when bulk editing files like JSON and yaml.