webpack: Add database/migrations handling

[Thor99]

Description

• add new entry point for database at webpackfile.js

• Change migrations path accordingly to the environment

Your checklist for this pull request

:rotating_light: Please review this items for a good pull request. :four_leaf_clover:

1. I've read the project's Contributing Guidelines
2. My commits are well written and follow pagarme/git-style-guide
3. My changes are well covered by tests and logs
4. I've updated the project docs (if needed)
5. I fell safe about this implementation
6. I feel confortable with the code I wrote, and I'm not ashamed to show it to my friends

In a good pull request, everything above is true :relaxed: