SolidLSP: Apply InitializeParamsBuilder across all remaining language servers

Convert every remaining SolidLanguageServer subclass from the old
_get_initialize_params method to the new _create_base_initialize_params
override, so common LSP initialize keys (processId, rootPath, rootUri,
clientInfo, workspaceFolders) are provided centrally by the
InitializeParamsBuilder rather than by each server.

- Drop the per-server processId/rootPath/rootUri/workspaceFolders and all
  clientInfo entries (including the VS Code spoofs in rust_analyzer and
  sourcekit); these are now set centrally.
- Preserve nested capabilities.workspace.workspaceFolders flags and any
  server-specific initializationOptions.workspaceFolders (e.g. kotlin,
  eclipse_jdtls).
- omnisharp keeps loading its JSON template but no longer sets the
  centrally-managed keys.
- Update _start_server call sites to self._create_initialize_params() and
  drop now-unnecessary cast()/type: ignore wrappers.

angular, svelte and vue are intentionally left as-is: they already override
_create_base_initialize_params for their TypeScript companion server, and
their remaining _get_initialize_params drives a separate language server
process.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

test/solidlsp/csharp/test_omnisharp_startup.py

@@ -1,35 +0,0 @@
-from __future__ import annotations
-
-from pathlib import Path
-from types import SimpleNamespace
-
-import pytest
-
-from solidlsp.language_servers.omnisharp import OmniSharp
-
-
-class _NoWaitEvent:
-    def is_set(self) -> bool:
-        return False
-
-    def wait(self, timeout: float | None = None) -> bool:
-        raise AssertionError("OmniSharp startup must not wait for dynamic capability registration")
-
-
-@pytest.mark.csharp
-def test_omnisharp_startup_does_not_wait_for_capability_registration(tmp_path: Path) -> None:
-    omnisharp = OmniSharp.__new__(OmniSharp)
-    omnisharp.repository_root_path = str(tmp_path)
-    omnisharp.server = SimpleNamespace(
-        send=SimpleNamespace(initialize=lambda _params: {"capabilities": {}}),
-        notify=SimpleNamespace(initialized=lambda _params: None, workspace_did_change_configuration=lambda _params: None),
-        on_request=lambda *_args: None,
-        on_notification=lambda *_args: None,
-        start=lambda: None,
-    )
-    omnisharp.server_ready = _NoWaitEvent()
-    omnisharp.definition_available = _NoWaitEvent()
-    omnisharp.references_available = _NoWaitEvent()
-    omnisharp.completions_available = _NoWaitEvent()
-
-    omnisharp._start_server()