feat: allow overriding checkly base url [kit-00]

[miliberlin]

Affected Components

• CLI
• Create CLI
• Test
• Docs
• Examples
• Other

Notes for the Reviewer

In order to support local development for the GitHub integration project, we need to be able to alter the Checkly base URL.
The GitHub integration flow opens a PR with changes on the user's codebase to add the Checkly CLI and add example GitHub action workflows running the test and deploy commands.
To test this locally, we expose and access the local backend via a tunnel (ngrok, cloudflare etc.), but the API URL is currently hardcoded to localhost and thus can't be accessed from a GH action.

Resolves #[issue-number]

New Dependency Submission

[miliberlin]

This is pretty much only needed for local development. Let me know if you prefer moving this to line 87 as local: process.env.CHECKLY_BASE_URL || 'http://127.0.0.1:3000'.
See the PR description for more context.

[ferrandiaz]

if we move it to 87 then the user also needs to add the env for local (so 2 envs) this way we override everything by just setting one env 👍

[sorccu]

I guess this works but how about the getMqttUrl below?

[miliberlin]

@sorccu good point! The local MQTT server also needs to be tunneled and the URL overwritten. I haven't worked on this part yet on the FE side. I'll put this PR back into draft until I've tested that fully.

[github-actions]

🎉 Experimental release successfully published on npm

npm install checkly@0.0.0-pr.1181.197ca16