Fix hover names from quoted definition snippets

[WilliamK112]

Summary:

• avoid using quoted string-literal definition snippets as hover display names
• prefer the semantic display name or callable metadata fallback, so signatures render as def array(...) instead of def 'array'(...)
• keep normal source-definition snippets unchanged and cover the quoted-name path with regression tests

Fixes #4004.

Test plan:

• cargo +stable-x86_64-pc-windows-gnu fmt --all --check
• cargo +stable-x86_64-pc-windows-gnu test -p pyrefly --lib lsp::wasm::hover::tests -- --nocapture
• cargo +stable-x86_64-pc-windows-gnu test -p pyrefly --test pyrefly_lsp_interaction_tests hover -- --nocapture
• cargo +stable-x86_64-pc-windows-gnu check -p pyrefly
• git diff --check