Improve file explorer indentation levels

[shreeve]

When looking at directories and files in the file explorer panel, the default indentation level is 12px. For many users, this default is not big enough and causes the nesting levels of the directories and files to be hard to figure out.

This patch simply increases the default file explorer indentation from 12px to 20px, yielding a much easier-on-the-eyes view of the files. Perhaps this value could go into a user setting and become configurable. Making this change directly in the code is much better than hacks such as slapping additional nasty css to the end of the vs/workbench/workbench.main.css file (which causes VS Code to complain that the installation has become corrupt).

On the image below, the left is the default and the right is what this change produces (ie - a visually more helpful level of indentation):

[shreeve]

The following animated GIF shows how the hierarchy grows and shrinks based on the value of the indent level. This screen capture was made using the older css hacks to adjust the indent level, whereas this current pull request directly updates the indent level in the code (and is thus much cleaner). However, this is included to show what the various sizes look like.

[shreeve]

Ah, just saw this (New Explorer: indentation at root has changed #66580)!

[isidorn]

Thanks for your PR, however we will discuss the issue here #66580
You also did a PR against an old tree so I am closing this as we do not plan to merge it in. Now we are using a new tree.

[shreeve]

@isidorn - Sounds GREAT! Thank you. I'm looking forward to using the new tree. Loving VS Code!

[isidorn]

Glad to hear.