[psteinroe]

Stacked on #988.

Removes code that nothing uses. I grepped for every item first. Clippy on the whole workspace is clean.

Removed

• AnnotationStore (pgls_workspace/src/workspace/server/annotation.rs). Every Document built one and pruned it with the parse and tree caches, but nothing read it. The field had #[allow(dead_code)], and get_annotations had #[allow(unused)]. Its only test tested the store itself.
• pgls_hover::OnHoverParams::ast. Hover never read it, but the workspace looked up the statement's tree to pass it. on_hover now maps the statement with WithCSTMapper, and WithCSTandASTMapper, which had no other user, is gone.
• HoveredNode::Trigger, which was never constructed (#[allow(unused)]).
• Snapshot::find_types in pgls_catalog, which had no callers.
• ClientInformation in pgls_lsp: initialize stored the client's name and version in the session, and nothing read them. They are still logged by the tracing::instrument on initialize.
• InitializeParams::workspace_folders in pgls_lsp's session (#[allow(unused)]). The session keeps the workspace folders in a field of its own, which is what everything reads.
• The pgls_console dependency of pgls_lsp, which nothing in the crate uses any more.

Simplified

In pgls_hover::on_hover, the table and type branches each had an arm for "no schema" and one for "schema" that only differed in passing None or Some(&s). They pass schema.as_deref() now, which is the same. The column branches really differ (alias resolution) and stay as they are.

Kept

• Document::count had an #[allow] but is used (completions). Only the attribute is removed.
• Migration::name is only read by tests, HoveredNode::Policy's payload is never read, but the variant stops policy names from being hovered as other objects, the #[allow(unused_variables)] on the execute_statement without db and the schema-only structs are cfg- or test-only. They are not dead.

Tests

pgls_workspace, pgls_lsp, pgls_hover and pgls_catalog pass, and so does clippy on the whole workspace.

Update: This is #977 again, rebuilt on #988 for the rebuild of the document caches and the walk. Since #977 was opened, print_markup was already removed on main, and InitializeParams::workspace_folders became unused because the session now keeps the folders separately, so it is removed here instead of kept. SQLFunctionSignature no longer exists on main.