add createSchema and dropSchema methods on MigrationInterface

[MasterOdin]

Closes #1870

Given that there's no docs right now for createDatabase either, did not elect to add them here (as not sure where to place them). For now, it should at least make it a bit easier for user discovery.

PR made against 0.13 due to breaking change on the MigrationInterface

[dereuromark]

If we add those freshly, couldnt we add the typehints? Or should we keep them off to be in sync with the other methods?

[MasterOdin]

I would say that the functions type hinting within the interface be consistent throughout the file, either all or nothing.

I do support in 0.13 to make the BC break here and add the type hints throughout the interface, especially given the larger BC break in #1872 already potentially going into 0.13. Alternatively, could hold off till 0.14 (or some future version), though I do think it should be done at some point.

[dereuromark]

Yeah, makes sense
What do others think?

[dereuromark]

So merging now, but I agree that 0.13 could and should add those typehints.

[Bilge]

It seems this is not available in seed files.

[MasterOdin]

The createDatabase and dropDatabase methods are also not available on the SeedInterface.

Just for my own edification, what's the use-case on wanting to create / drop schemas as part of seeding, and not the migration process?

[Bilge]

See #2161.

Aside, I don't understand why seeding and migration don't share the same API.

[MasterOdin]

For #2161, the end result of what you'd want is that:

1. phinx itself doesn't care about the migration table's existence when running seeds
2. that you would have a method to easily create the schema for the phinx migration table

Aside, I don't understand why seeding and migration don't share the same API.

Agreed now that I've looked at them more closely.