Implement Endpoint command

[owenthereal]

Description of change

Implement Endpoint command. Client library is in https://github.com/meroxa/meroxa-go/pull/19. Server part is in https://github.com/meroxa/platform-api/pull/189.

$ meroxa create endpoint my-endpoint --protocol grpc --stream resource-2-499379-public.accounts
$ meroxa list endpoint
    NAME       PROTOCOL                STREAM                                                            URL                                               READY
============= ========== =================================== ============================================================================================ =======
       hello   GRPC       resource-2-499379-public.accounts   host=endpoint.test username=c10o5nrvevu3h1n6kkj0 password=X203gdSc7b94m1CM6FpNHLB8uyVKr5kU   True
 my-endpoint   GRPC       resource-2-499379-public.accounts   host=endpoint.test username=c10o763vevu3h1n6kkjg password=3WJx1BLR08AIqv7sQYUGyT9DzSr625M4   True
        owen   HTTP       resource-2-499379-public.accounts   https://c10jf5bvevu3h1n6kkig:ml163t7qvzETQfMWC4Lj28cF0k9agY5n@endpoint.test                  True
$ meroxa describe endpoint owen
 NAME   PROTOCOL                STREAM                                                     URL                                       READY
====== ========== =================================== ============================================================================= =======
 owen   HTTP       resource-2-499379-public.accounts   https://c10jf5bvevu3h1n6kkig:ml163t7qvzETQfMWC4Lj28cF0k9agY5n@endpoint.test   True
$ meroxa delete endpoint hello

Type of change

• New feature
• Bug fix
• Refactor
• Documentation

How was this tested?

• Manual Test
• Unit Tests
• Deployed to staging

[raulb]

Something I forgot mentioning as part of this PR was to provide feedback to the user when things were happening (e.g.: "Creating endpoint... Endpoint created", etc...

I'll open a separate a PR as soon as I wrap up what I'm working on.