Ship modifications for running the Connector Builder Server against local CDK

[clnoll]

Extend the pattern that we use for running the SATs against the local CDK to the Connector Builder server.

Note: this should be done after shipping the SAT updates, in case we want to make slight changes during development.

This will involve:

1. Adapting the script for creating connector images with the local CDK for the Connector Builder server. The script should take an environment variable that indicates where the CDK is located to future-proof us against the Connector Builder server moving to the Cloud monorepo.
2. Update the CDK version used by the webapp (see connector builder FE should consume a versioned artifact of declarative_component_schema.yaml #21830).
3. Creating a gradle task and/or updating the docker-compose.yml to run the Connector Builder server image created by 1.
4. Creating a gradle task to run tests against the Connector Builder server image created by 1.
5. Update documentation.

Proof of concept

[clnoll]

When discussing this ticket we decided that there were a few reasons it wasn't high priority:

1. The Connector Builder server is going to be split into a separate repo, so the flow will necessarily be different.
2. We're about to launch the Java server for interfacing with the CDK via Docker; we'll have to alter the setup once that's underway.
3. Testing the Connector Builder server against the local CDK (locally) is not difficult/time-consuming.

Based on that, I'm closing this issue and will open one for running the CB server against a development version of the CDK in CI, which is higher priority.