✨ [FEAT] add common dev profile to the `pyproject.toml` configuration

[renardeinside]

If several users develop the same project, they might prefer to have a standard, project-wide profile name.

example design:

[tool.apx.metadata]
dev-profile="some-profile"

Conceptually:

1. pass the profile into _metadata.py
2. applying logic: read, add to the env dict in rust under DATABRICKS_PROFILE key. if user has this key in .env, info and continue with .env (takes precedence). If this env variable is already set while starting, e.g.:

DATABRICKS_PROFILE=xyz uv run apx dev start

then the one passed from the command also takes precedence (again, print an info message).

Potentially should only change src/cli/dev/start.rs.