feat: Add Swift language analyzer

[Verduttio]

Introduced two new metrics, implemented additionally in Swift analyzer:

• function count
• average function name length.

[vladfedoriuk]

[vladfedoriuk]

Please, provide the fixes to the imports, similarly to https://github.com/Software-Engineering-Jagiellonian/django-celery-frege-poc/pull/53

[vladfedoriuk]

Please, fix the merge conflicts. Should the conflicts be resolved, I will merge a PR.

[Verduttio]

Please, provide the fixes to the imports, similarly to #53

Done

[Verduttio]

Please, fix the merge conflicts. Should the conflicts be resolved, I will merge a PR.

Resolved

[vladfedoriuk]

There are some new conflicts, please resolve them as well.

[Verduttio]

There are some new conflicts, please resolve them as well.

Done

[Verduttio]

[vladfedoriuk]