Feature Request: date range filtering

[k-funk]

Would be nice to combine date range filtering in addition to labels. ie: before:2004/04/18, after:04/16/2004. Might require some refactoring for the CLI to support a combination of filters, perhaps a series of questions:

1. filter by mailId
2. filter by label
3. filter by before
4. filter by after

if none are selected, then they'll get 'all'

Docs:
https://developers.google.com/gmail/api/guides/filtering
https://support.google.com/mail/answer/7190