Allow --file param on `azd provision`

[jongio]

I often need to provision one off artifacts, like roles, and need azd context when doing so.

Scenario - env sharing

User creates env User shares env User 2 runs azd env refresh User 2 doesn't have right roles User 2 needs to run something like azd provision --file roles.bicep to get roles.

Right now a custom script is required to unlock this common scneario.