Foreman Maintain

Fixes #20848 - Fix error messages indentation

Support for run_once procedures and repositories setup

Rollback support if the upgrade fails soon enough

Extract control flow of upgrades to special file

Introduce run_strategy for scenarios

Health-check scenarios are better to run all steps regardless of errors
(:fail_slow strategy), while the migration scenarios should fail as soon
as first failure happens (:fail_fast strategy).

By default, the scenarios are treated as `:fail_fast`.

Full upgrade scenario

This commit intoroduces more structured upgrade scenario consisting of
this scenarios:

• pre_upgrade_check - non-modifying checks: is the system ready?
• pre_migrations - modifying procedures before source update
• migrations - source update and main migrations...

Fixes #44 - Change tag 'basic' to 'default'

Fixes #3 - Add option to skip the prompted step

Run confine against classes, not objects

This allows us to have multiple objects of the same procedure in the
system, differing in the constructor parameters. Useful for parametrized
procedures.

Extract metadata DSL to separate namespace

Having the DSL methods directly on the classes caused issues when
needing to query the metadata later.