Add command to auto-add rule ignore to `pyproject.toml`

[janosh]

If the extension detects a pyproject.toml file with

[tool.ruff]
ignore = ["..."]

would be great if the dropdown from pressing cmd+. on a violation offered a way to insert the rule code into the ignore list. I.e. in this screenshot, there should be a new option below "Disable for this line" to disable globally.

[dhruvmanila]

Related: #253