[FEAT] Adds support for constraints in relationships. [FIX] Replacing .yml in filenames.

[ghosthi]

What kind of change does this PR introduce? (pls check at least one)

• Bugfix
• Feature
• Code style update
• Refactor
• Build-related changes
• Other, please describe below

Description

This PR fixes the replace on .yml file titles on migrations that used to be replaced with rtrim, which can lead to unexpected behaviour on Schemas with names ending with characters "y", "m" or "l".

This PR also introduces the feature of allowing the use of constraints in Schema Relationships without changing the previous behaviour.

Using the previous format on schema files like so

# you can add foreign ids for other models under the relationships key key
relationships:
  - User

Will allow creation of relationship columns as usual.

With this PR, using it like this:

relationships:
  - User: id
  - Role: id

Will allow constrained relationships (with foreign key referenced) in the database.

Does this PR introduce a breaking change? (check one)

• Yes
• No

Related Issue