Add regional form evolution details

[jemarq04]

Change description

This PR adds evolution details regarding all regional forms (Alola, Galar, Hisui, and Paldea) including some related region-specific evolutions (e.g. Cyndaquil to Quilava at level 17 instead of 14, but only in Hisui).

This is related to issue #1396. In addition to new evolution details, region_id and base_form_id are renamed to be region and base_form to be consistent with other fields (similar to PR #1487). The base_form field was changed to a Pokemon model so that regional forms could be specified. These fields were also missing from tests, so they were added as well.

An unintended consequence of this is that the latest evolution detail will not necessarily reflect the current evolution (like the Cyndaquil example I gave previously). At some point I'd like to add something to make the current evolution method clearer (maybe even accessible by version group?) but while I tinker with that these additions should be added.

Contributor check list

• I have written a description of the contribution and explained its motivation.
• I have written tests for my code changes (if applicable).
• I have read and understood the AI Assisted Contribution guidelines.
• I will own this change in production, and I am prepared to fix any bugs caused by my code change.

[daniilmastrangeli]

@Naramsim can u check this PR, please?

[pokeapi-machine-user]

A PokeAPI/api-data refresh has started. In ~45 minutes the staging branch of PokeAPI/api-data will be pushed with the new generated data.

The staging branch will be deployed in our staging environment and the entire API will be ready to review.

A Pull Request (master<-staging) will be also created at PokeAPI/api-data and assigned to the PokeAPI Core team to be reviewed. If approved and merged new data will soon be available worldwide at pokeapi.co.

[pokeapi-machine-user]

The updater script has finished its job and has now opened a Pull Request towards PokeAPI/api-data with the updated data.

The Pull Request can be seen deployed in our staging environment when CircleCI deploy will be finished (check the start time of the last build).