feat: add plural filter

[dinosath]

Add a custom filter for pluralizing a word

[dinosath]

@kstasik what do you think? I did not find another way to get the plural of a word apart from custom filter. It can be used in cases of coding conventions where the plural is used e.g. sql

[kstasik]

it's fine with me.

• Please make sure your commit follows https://www.conventionalcommits.org/en/v1.0.0/
• Fix lints
• And make the dependency optional, needed only by codegen itself

And we can merge if if you need it.