Update recipe schema for new globs and `files`

[wolfv]

This adds the following:

build:
  files:
    # select files to include based on a glob expression
    - foo/*

It also extends the glob definition (in rattler-build that's the GlobVec type). You can use either a single glob, a list of globs (treated as include globs) or a map with include and exclude globs.

files: foo/*
# or 
files:
  - foo/*
# or 
files:
  include:
    - foo/*
  exclude:
    - *.txt

All three forms are valid in PR https://github.com/prefix-dev/rattler-build/pull/819

Note: CEP has to be updated as well.