Add CodeAction codeActionLiteralSupport Feature (#4163)

* Advertise codeActionLiteralSupport to LSP server

Without this, rust-analyzer doesn't return any code actions.  With it,
everything works properly.

* linter fixes

* test cases fixes

* Fix underflow of column in position.

Special values like for example -1 to denote the end of a line are not supported.
[reference](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#position)

Co-authored-by: Brian Gernhardt <brian@gernhardtsoftware.com>

test/lsp/test_lsp_startup.vader

@@ -194,6 +194,11 @@ Before:
       \           },
       \           'codeAction': {
       \             'dynamicRegistration': v:false,
+      \             'codeActionLiteralSupport': {
+      \                  'codeActionKind': {
+      \                      'valueSet': []
+      \                  }
+      \              }
       \           },
       \           'rename': {
       \             'dynamicRegistration': v:false,