Add symbol extraction for functional, dynamic, and systems languages

[Widthdom]

Summary

• Add conservative symbol extraction for Clojure, Erlang, OCaml, and Raku.
• Add conservative symbol extraction for Crystal, Groovy, Julia, and Tcl.
• Add conservative symbol extraction for Ada, D, and Nim, while keeping reference extraction and graph queries disabled for these symbol-only languages.
• Add determinism-test fixtures for the new pattern languages after merging the latest origin/main.

Validation

• dotnet run --project tools/CodeIndex.Changelog -- check
• dotnet test tests/CodeIndex.Tests/CodeIndex.Tests.csproj --configuration Release --framework net9.0 --filter "FullyQualifiedName~SymbolExtractorTests.Extract_AllPatternLanguages_IsDeterministicUnderParallelCalls" -p:UseSharedCompilation=false
• dotnet test tests/CodeIndex.Tests/CodeIndex.Tests.csproj --filter "FullyQualifiedName~SymbolExtractorTests.Extract_FunctionalLanguages_IndexConservativeDeclarations_Issue3527|FullyQualifiedName~SymbolExtractorTests.Extract_DynamicLanguages_IndexConservativeDeclarations_Issue3528|FullyQualifiedName~SymbolExtractorTests.Extract_SystemsLanguages_IndexConservativeDeclarations_Issue3529|FullyQualifiedName~SymbolExtractorTests.Extract_AllPatternLanguages_IsDeterministicUnderParallelCalls|FullyQualifiedName~QueryCommandRunnerTests.RunLanguages_Json_SearchOnlyBucketsAdvertiseZeroSymbolAndGraphSupport" -p:UseSharedCompilation=false
• dotnet test tests/CodeIndex.Tests/CodeIndex.Tests.csproj --filter "FullyQualifiedName~SymbolExtractorTests.BuiltInSymbolRegexes" -p:UseSharedCompilation=false
• dotnet build
• dotnet ./src/CodeIndex/bin/Debug/net8.0/cdidx.dll status --check --json

Changelog

• changelog.d/unreleased/3527.added.md
• changelog.d/unreleased/3528.added.md
• changelog.d/unreleased/3529.added.md

Fixes #3527
Fixes #3528
Fixes #3529