feat(vscode): better metachema UI, stop re-rendering, spinner component and related tests

[Karan-Palan]

Screen recording/Screenshots:

https://json-schema.slack.com/files/U087E6ZE95G/F09N04UBSKG/screencast_from_2025-10-23_02-35-43.mp4

Changes made:

1. Loading Spinners (Webview displays spinner during analysis, then smoothly transitions to results
   Works perfectly for huge schemas where CLI takes time)
2. Clickable Linting and Metaschema warnings that navigate to error positions (updated cli to version 11.11.1)
3. Red Squiggly lines for Metaschema errors, Yellow warnings for lint
4. Metaschema card design is now similar to linting card design
5. Added a configuration section in package.json to disable VS-code's built in JSON validation.
   Extension automatically disables json.validate.enable on activation
6. Removed all unnecessary re-renders and jankiness when clicking a button, or changing files
7. Format button just re-renders formatted state ; initially all tabs (lint, health, metaschema, format) show "?"
8. Fixed edge cases found by testing on large schemas
9. Updated test suite

Tests present:

1. Extension Core (6 tests)

• Extension presence and activation
• Command registration
• Diagnostic collection creation
• Panel opening
• JSON file handling

2. FileUtils (22 tests)

• File validation (7 tests): null paths, extensions, spaces
• Lint result parsing (4 tests): valid/invalid JSON, errors
• Metaschema result parsing (8 tests):
  • Exit codes 0, 1, 2
  • JSON extraction with prefix/suffix text
  • Empty arrays
  • Field preservation
• Position conversion (3 tests): ranges, multi-line, boundaries

3. DiagnosticManager (13 tests)

• Creation and disposal
• Lint diagnostics with warnings
• Metaschema diagnostics with errors
• Position filtering
• Clearing diagnostics
• Clickable code links
• Optional field handling

4. PanelManager (8 tests)

• Lifecycle management
• State updates
• Message handling
• Disposal

5. CommandExecutor (7 tests)

• All CLI command methods
• Version retrieval
• Lint, format, formatCheck, metaschema

6. Types (3 tests)

• DiagnosticType constants
• Type uniqueness