Also includes a comment on Ci::Config regarding that's going to be
override by EE

- Create ci/lints controller inside project/
- Move js pages to be inside projects/
- Copy view ci/lint view to be inside project folder
- Remove ci/lint view and js files

Closes #43603

This also makes Script to return an array of commands instead of
concatented command, which is our current direction.

This makes use of `ActiveModel::Validations` encapsulated in a separate
class that is accessible from a node object.

This reverts commit 13e37a3e.

This is a temporary refactoring stub, that is planned to be removed
after removing legacy config processor.

With this approach it would be easier to add different sources of
configuration, that we do not necessairly have to be in YAML format.

As for now, we keep this class inside a oryginal config processor class.
We will move implementation to this class and delegate to it from
current config processor.

After original gitlab ci yaml processor not longer has relevant
impelemntation we will replace it with new configuration class.