[Feature Request] Support updating metadata of a collection

[jackwilsdon]

Description

Currently, metadata on a collection can only be set at creation time.

Steps to reproduce

N/A

Expected Behavior

Able to update metadata on a collection when making a PATCH /collections/<name> request.

Actual Behavior

Cannot update metadata on a collection.

Metadata

Typesense Version: 26.0

OS: Docker on macOS, typesense/typesense:26.0 image