refactor & removal of legacy `analyzer`

[ndonfris]

High-Level Summary

• Analyzer method analyze will potentially contain more functionality to support src/features/*, by storing relevant context in it's analyzedDocument type.

• Analyzer definition should be able to accomplish the same functionality it currently supports, while becoming significantly smaller. Thanks to everyone who provided contributions to make this possible!

• This PR's goal is to remove most, if not all, of the remaining currently defined fragile components in the lsp.

---

[!IMPORTANT] Refactoring src/analyzer.ts will change various components within the project, and allow for more features to be supported by the server. Features like code-actions, quickfixes, and context specific diagnostics might be included in this PR.

This rewrite of the analyzer will include improvements for supporting edge cases specifically related to the various methods fish provides to define variables (with proper scope) including:

• set/read flags: -l/--local, -g/--global, -U/--universal, -f/--function
• the argparse command

  allowing for a function's completions to be auto-generated, plus many other things

• function flags: -V/--inherit-variable, -a/--argument-names, -v/--on-variable, -S/--no-scope-shadowing
• generated variable scoping: $status, $pipestatus, $argv

Tasks

• [ ] refactor analyzer.ts structure (replace with analyzer-future.ts once completed)

  • [x] clarify analyzer.ts scope, for easier maintaince. Prior to this PR, the analyzer's structure is difficult to extend (at best). Multiple methods on the Analyzer could be moved to a more appropriate location.
  • [x] move important tree-sitter related functions in Analyzer to be defined in src/utils/tree-sitter.ts
  • [x] reflect changes towards server.ts to match new Analyzer class

• [x] provide a single data structure for DocumentSymbol & WorkspaceSymbol

  • [x] remove document-symbol.ts
  • [x] remove workspace-symbol.ts
  • [x] create a file named symbols.ts to handle building symbol list, and converting DocumentSymbol[] to WorkspaceSymbol[]

• [x] remove generic-tree.ts. This file has become less useful, and overall adds clutter to places that need such an algorithm.

• [x] add sourcing files (source ~/.config/fish/some_file.fish) support to our per-document analysis, provided during the analyzer.analyze stage of incremental document indexing

  should be possible by the same sequence of operations used in the diagnostics/node-types.ts

• [ ] rework workspace.ts to reflect changes towards analyzer structure

• [x] add utilities with matching tests to new symbol.ts file.

  • [x] build composite nodes FishDocumentSymbol[] from LspDocument
  • [x] support flattening any symbol (FishDocumentSymbol[] or FishWorkspaceSymbol[]) efficiently

    FishWorkspaceSymbol, WorkspaceSymbol, or SymbolInformation do not support nested children properties. In the current definition, these global types already expect a flat array.

  • [x] support translation operation between symbols.
  • [x] support finding FishWorkspaceSymbol[] from documents FishDocumentSymbol[], symbols which are globally scoped (including, autoloading, explicit definitions, etc.)
  • [x] filtering a nested Symbol for connecting child nodes with parents, that could possibly not be directly related.
  • [x] proper test coverage, in symbol.test.ts to ensure future changes match expected behavior
  • [x] reimplement multiple WorkspaceSymbol utilities like findDefinitionSymbol, getReferenceLocation, removeLocalSymbols & findGlobalLocations
  • [x] add getReferenceLocation to this.analyzer in src/server.ts usage
  • [x] add findDefinitionSymbols to this.analyzer in src/server.ts usage

• [x] remove local CompletionItem related files from src/utils/completions/. Local symbols will be resolved by the new syntax below:

  Potentially needs to make use of utilities for Symbol[], like flattenSymbols()

  const allSymbols: FishDocumentSymbol[] = [] // getAllSymbols()
  /* const currentSymbol = getCurrentSymbol() */
  const currentScope = currentSymbol.scope.parent;
  /** lookup & store symbols that are closest to the current scope */
  const result = allFilter.filter(symbol => symbol.range.isWithin(currentScope.range))
  /* use `result` to build local Completions, Signatures, Hovers, etc... */