Use language_server-protocol gem's SymbolKind constants

[st0012]

Motivation

Instead of maintaining our own list of symbol kinds, we can use the language_server-protocol gem's SymbolKind constants, which will reduce a layer of conversion (symbol to integer) as well.

[github-actions]

Benchmark results in seconds (slowest at top)

          textDocument/completion average: 0.204193 std_dev: 0.003472
          textDocument/diagnostic average: 0.042897 std_dev: 0.010538
          textDocument/definition average: 0.004928 std_dev: 0.002845
      textDocument/selectionRange average: 0.004203 std_dev: 0.000612
   textDocument/documentHighlight average: 0.002659 std_dev: 0.000198
      textDocument/documentSymbol average: 0.002603 std_dev: 0.000204
            textDocument/codeLens average: 0.002562 std_dev: 0.000201
        textDocument/documentLink average: 0.002559 std_dev: 0.000202
 textDocument/semanticTokens/full average: 0.002544 std_dev: 0.000362
        textDocument/foldingRange average: 0.002506 std_dev: 0.000229
textDocument/semanticTokens/range average: 0.001702 std_dev: 0.000136
               codeAction/resolve average: 0.001484 std_dev: 0.000122
           textDocument/inlayHint average: 0.001433 std_dev: 0.000128
               textDocument/hover average: 0.001419 std_dev: 0.000108
    textDocument/onTypeFormatting average: 0.000878 std_dev: 8.1e-05
          textDocument/formatting average: 0.000875 std_dev: 0.000164
          textDocument/codeAction average: 0.000851 std_dev: 7.7e-05


================================================================================
Comparison with main branch:

 textDocument/semanticTokens/full unchanged
textDocument/semanticTokens/range unchanged
      textDocument/documentSymbol unchanged
        textDocument/foldingRange unchanged
          textDocument/formatting unchanged
          textDocument/diagnostic unchanged
        textDocument/documentLink unchanged
           textDocument/inlayHint unchanged
      textDocument/selectionRange unchanged
   textDocument/documentHighlight unchanged
               textDocument/hover unchanged
          textDocument/codeAction unchanged
    textDocument/onTypeFormatting unchanged
               codeAction/resolve unchanged
          textDocument/completion unchanged
            textDocument/codeLens unchanged
          textDocument/definition unchanged


================================================================================
Missing benchmarks:

RubyLsp::Requests::ShowSyntaxTree

[vinistock]

Nice