A new test framwork with a ULSP test suite

[Jafaral]

Add a complete test suite for the Unicon Language Server Protocol (ULSP)
implementation with four main test categories:

1. JSON-RPC Tests (jsonrpc_test.icn)

   • Tests JSON-RPC protocol with calculator server
   • Validates concurrent request handling
   • Tests basic arithmetic operations

2. LSP Message Tests (lsp_message_test.icn)

   • Tests JSON-RPC message parsing and validation
   • Tests all LSP request/response message types
   • Tests notification handling
   • Tests error handling and malformed message rejection

3. LSP Feature Tests (lsp_feature_test.icn)

   • Tests LSP features with realistic Unicon code
   • Tests completion, hover, definition, symbols, formatting, folding
   • Tests signature help functionality
   • Uses LSPDB for symbol information

4. LSP Protocol Tests (lsp_protocol_test.icn)

   • Integration tests with actual server-client communication
   • Tests server initialization and capability negotiation
   • Tests document synchronization (didOpen, didChange, didSave)
   • Tests end-to-end LSP feature workflows

Unified Test Runner (lsp_run_tests.icn):

• Executes all four test suites sequentially
• Aggregates test counts from all suites
• Provides comprehensive test reporting
• Supports individual test suite execution

Test Framework Features:

• Expected result capture mode with JSON output
• Deep comparison for expected vs actual results
• JSON-formatted error reporting
• Consistent test structure across all test files
• Proper Unicon success/failure semantics

Makefile Integration:

• Individual test targets for each test suite
• Unified test runner target
• Clean targets for test artifacts

All test files follow consistent structure:

• Test class with run_all_tests() method
• Global counters for test tracking
• Standalone execution support via $ifdef STANDALONE

[Don-Ward]

Perhaps it makes sense to defer a review until the CI runs without errors -- either because the underlying cause of the CI failures have been fixed, or the ULSP tests are explicitly disabled for the configurations that currently fail.