feat(glides): add uiVersion to event metadata

[andrewdolce]

Asana Ticket: Add a new "UI version" field to the glides.trips_updated message sent to LAMP

See accompanying Glides PR https://github.com/mbta/glides/pull/3287 for the implementation of this proposal. (I will wait for feedback and approval on the schema change here before merging that.)

Adds a uiVersion field to Glides events metadata. This is expected to be a non-breaking change. Some more notes:

• The field is a string to allow for flexibility rather than locking into a particular versioning scheme. Glides team will be responsible for maintaining the canonical set of expected values.
• Like all event metadata fields, this one is optional. We expect to populate it on trips_updated going forward, but not on other events unless it becomes necessary.