Load hook metadata from YAML without importing Hook class

[yuseok89]

Closes: #61815

Loading the Connection Add page is slow on the first uncached request because hook_meta_data() imports Hook classes for every connection type. With 129+ providers, this cost becomes significant before the response can be cached.

This PR changes the GET /ui/connections/hook_meta response so it no longer imports Hook classes and instead uses only the metadata from provider.yaml via _load_ui_metadata(). This was made possible by @amoghrajesh 's provider.yaml migration, which moved connection UI metadata into YAML.

In this change, hook-name is added to connection-types in provider.yaml for display in the connection type dropdown (falls back to connection_type when absent).

Before

Screen.Recording.2026-02-12.at.9.34.40.PM.mov

After

Screen.Recording.2026-03-18.at.11.04.44.PM.mov

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