Display Linting Error Hints in Editor Tab

[Standlc]

Currently, when a file has linting errors, a red cross is displayed over its icon in the codebase tree (project panel).
It would be useful to also make its name in the editor tab red, as well as show the number of errors in the file.

Here is screenshot of zed. We can see turbopuffer.py has errors by the little red cross in the tree item, but the tab doesn't indicate there is any issue.

In VSCode however, the tab name is red and we can also see the number of errors in the file.

This makes it so much easier to detect which open files have problems. Really miss that 🥲.

[SomeoneToIgnore]

zed/assets/settings/default.json

Lines 1031 to 1041 in 35f5eb1

	// Which files containing diagnostic errors/warnings to mark in the tabs.
	// Diagnostics are only shown when file icons are also active.
	// This setting only works when can take the following three values:
	//
	// 1. Do not mark any files:
	// "off"
	// 2. Only mark files with errors:
	// "errors"
	// 3. Mark files with errors and warnings:
	// "all"
	"show_diagnostics": "off"