Use internal SQLite3 database

[vovimayhem]

[Closes #50]
[Closes #69]
[Closes #19]

Background

Replaces the PostgreSQL database with an internal SQLite database, as the data is typically read-only while running on servers, and updates can be deployed as part of the code. Also, it will fix some open issues.

Features

1. Migrate DB from Postgresql to SQLite.
2. Add an index to ZipCodes to full-text search inside SQLite
3. Fix issues in searches caused by migrating between DBs
4. add items per-page parameter to add flexibility when you require more than 15
5. deployment has set from GCP to Azure, avoiding artifact registry, to save costs, now it uses Dockerhub
6. No more PR deployments to save costs in the cloud
7. upgrade DB from correos de México records

Conclusion

After those features, we got a renewed API to request the different Zip Codes inside Mexico.

[vovimayhem]

The only thing not working that good is the "zip code" filtering functionality... here are some links with info related to how I'm planning to solve it:

• https://www.sqlite.org/fts5.html
• https://www.sqlitetutorial.net/sqlite-full-text-search
• https://viblo.asia/p/rails-full-text-search-with-sqlite-OeVKBvvEKkW

Following the examples of the first link, I validated that looks like a viable replacement for the "unaccent" extension in PostgreSQL... but will deviate from the "standard" activerecord practice... meaning more SQL...