Fix installing Jockey as a dependency and introduce AZ filter

[peterctl]

Description

This PR includes 2 changes.

1. It allows Jockey to be installed as a Pip dependency using this notation:

pip install git+https://github.com/lcvcode/jockey

2. It introduces an AZ filter which will filter machines and units by availability zone.

jockey units charm=nova-compute az=az1

Type of Change

• [ X ] New feature
• [ X ] Bug fix

Testing

Testing was performed manually.

Impact

No impact should be introduced by this PR.

[github-actions]

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