Fix build issues - Githubissues

This PR fixes a few issues preventing the app from building successfully:

Updates the version of @angular/flex-layout to match the framework major version as this was causing a dependency conflict.
Reinstates the environment config with removed API keys. This would be a hurdle to contributions. The API keys were unused and can be included via another method, ideally during the release process, if necessary later.
Increase max initial build size in the production environment. The previous limit was exceeded, failing the build. This could do with further investigation.

It also makes a few changes to improve developer experience:

Ignore build assets (dist / angular cache) to prevent accidental commit
Moves all TypeScript type stubs to devDependencies. They aren't needed following build.
Removes deprecated @types/maplibre-gl to prevent build warning
Remove enableProdMode call. This was deprecated in Angular 15 and is set by the build config in angular.json.

Ideally the DX changes would have been in a separate PR, but it is what it is. I can extract them if required.

airgradienthq / map