Update Core & add HTTP Otel / Dev UI Port

[Sushisource]

What was changed

• Added ability to specify UI port in dev server startup
• Added ability to select HTTP protocol for Otel metrics export

Why?

Checklist

1. Closes [Feature Request] Allow customization of dev server UI port #396
   closes [Feature Request] OTel metrics over HTTP #392

2. How was this tested:
   Core tests should be sufficient. Manually verified UI port is set properly.

3. Any docs updates needed?

[cretz]

Nice, thanks for knocking out some of my issues while here. Only a couple of minor comments.

[cretz]

Not required, but could make this a nested enum inside the OpenTelemetryOptions as just Protocol if you'd like, but here is fine too

[Sushisource]

I stuck with what temporality did

[cretz]

Can we surround this with the if-not-null check? Hopefully as of #405 CI will break anyways. (EDIT: it does break in CI, whew)

[Sushisource]

Will do. IMO these should all just check for nullity internally. Feels a bit silly to protect all of them individually.

[cretz]

I'd be ok with that change if you want to make it or open an issue for us to make it later. I think originally I was unnecessarily trying to reduce call counts.

[cretz]

Approving. Don't like the new top-level file, but not a big deal.