feat: Sync nvim-tree across tabs

[rwblokzijl]

This PR syncs nvim tree across tabs if open_on_tab is set.

Previously:

• On tab change this would open nvim-tree
• When having closed nvim-tree it would still open nvim tree on tab change

Now:

• when having closed nvim-tree it will sync this on tab change
• if nvim-tree is closed (using :quit) this is also synced across tabs
• if nvim-tree is the final window in a tab, the tab is closed (if this is the last tab, vim is closed)

[alex-courtis]

• if nvim-tree is the final window in a tab, the tab is closed (if this is the last tab, vim is closed)

This was present in the past however was removed as it is unavoidably problematic. #1005 (comment)

You may implement this functionality yourself: https://github.com/nvim-tree/nvim-tree.lua#tips--tricks

[alex-courtis]

We do not use global variables to track nvim-tree state.

Please test via something like:

• iterate windows on tab
• test utils.is_nvim_tree_buf

[alex-courtis]

I've not tested nor fully reviewed yet.

Please:

• remove auto close
• avoid global variable
• resolve stylua issues as per https://github.com/nvim-tree/nvim-tree.lua/blob/master/CONTRIBUTING.md

[rwblokzijl]

Closed by force push i think. See #1698

[alex-courtis]

Please don't force push. Rebase or merge your branch instead.