Create charmcraft-specific versions of the upstream `python` and `poetry` plugins

[lengau]

What needs to get done

Basically the plugin work done in https://github.com/canonical/charmcraft/pull/1840 needs to be tested and expanded to the python plugin too.

Why it needs to get done

Decoupling from the charm plugin.

[syncronize-issues-to-jira[bot]]

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The internal ticket has been created: https://warthogs.atlassian.net/browse/CRAFT-3361.

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[lengau]

These will also need to include:

• Strict dependencies (mandatory on - using equivalents of pip --no-dependencies)
• Builds from source