Improve editor tabs and project panel items

[nervenes]

Continuation of #16615 and #16671

Notes

previously, the git_status option in both project_panel and tabs settings was used to toggle git coloring, this option name is a bit misleading now with git symbols in place which are the actual statuses, so i've changed git_status to toggle the git symbols on and off instead (to avoid a breaking change). for git coloring, i've added a new option called git_colors that can be toggled.

• both git_status and git_colors default to true in both project_panel and tabs.
• i've also defaulted file_icons in tabs to true for a more consistent relation with the project_panel.

Screenshot

Release Notes:

• Added git symbols to the project panel and editor tabs, the git_status option now refers to git symbols, with an added git_colors option for coloring, both are set to true by default. (#20134)
• Added symlink symbol to editor tabs. (#20134)
• Disable the dirty buffer indicators in tabs when autosave is enabled. (#20134)
• Improved the editor tabs layout. (#20134)
• Changed file_icons in tabs to default to true. (#20134)

[nervenes]

cc @mrnugget @iamnbutler

i recommend running the branch locally to see how things have changed

[mrnugget]

Before I dive in too deep: have you seen the discussion in #18182 on icons in the project panel?

[nervenes]

Yep, i left a comment: #18182 (comment)