Add refactorings cia clojure-lsp

[PEZ]

What has Changed?

Add the follownig refactorings

Adds:

• 'clean-ns'
• 'add-missing-libspec'
• 'cycle-coll' (Probably Calva's re-wrap commands are better for this)
• 'cycle-privacy'
• 'expand-let'
• 'thread-first'
• 'thread-first-all'
• 'thread-last'
• 'thread-last-all'
• 'unwind-all'
• 'unwind-thread'
• 'introduce-let'
• 'move-to-let'
• 'extract-function'

This PR also adds a progress notification fo indicating that the LSP server is unavailable while it is starting.

Fixes #798
Fixes #861
Fixes #892
Fixes #598
Addressing #137

I have:

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• Made sure I have changed the default PR base branch, so that it is not master. (Sorry for the nagging.)
• Updated the [Unreleased] entry in CHANGELOG.md, linking the issue(s) that the PR is addressing.
• Figured if anything about the fix warrants tests on Mac/Linux/Windows/Remote/Whatever, and either tested it there if so, or mentioned it in the PR.
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  • Tested the particular change
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  • Smoke tested the extension as such.
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• Created the issue I am fixing/addressing, if it was not present.
• Added to or updated docs in this branch, if appropriate

The Calva Team PR Checklist:

Before merging we (at least one of us) have:

• Made sure the PR is directed at the dev branch (unless reasons).
• Figured if anything about the fix warrants tests on Mac/Linux/Windows/Remote/Whatever, and tested it there if so.
• Read the source changes.
• Given feedback and guidance on source changes, if needed. (Please consider noting extra nice stuff as well.)
• Tested the VSIX built from the PR (well, if this is a PR that changes the source code.)
  • Tested the particular change
  • Figured if the change might have some side effects and tested those as well.
  • Smoke tested the extension as such.
• If need be, had a chat within the team about particular changes.

Ping @PEZ, @kstehn, @cfehse, @bpringe