Fix member.ban and TypeError in guild.ban

[NeloBlivion]

Summary

Since delete_message_seconds default was changed to None, you run into a TypeError when it isn't passed in.

> await member.ban()

File ".../venv/lib/python3.8/site-packages/discord/member.py", line 665, in ban
  await self.guild.ban(self, reason=reason, delete_message_days=delete_message_days)
File ".../venv/lib/python3.8/site-packages/discord/guild.py", line 2973, in ban
  if not (0 <= delete_message_seconds <= 604800):
TypeError: '<=' not supported between instances of 'int' and 'NoneType'

As such, the default is changed back to 0. Regarding a concern raised in the original PR, if the defaults are 0 then the data won't be set anyway.

        if delete_message_seconds:
            params["delete_message_seconds"] = delete_message_seconds
        elif delete_message_days:
            warn_deprecated(...)
            params["delete_message_days"] = delete_message_days

This PR also updates Member.ban to support delete_message_seconds as it seemed to be untouched... as such, all member.ban calls in 2.2.0 may currently be broken.

> await member.ban(delete_message_seconds=0)
TypeError: Member.ban() got an unexpected keyword argument 'delete_message_seconds'

Information

• This PR fixes an issue.
• This PR adds something new (e.g. new method or parameters).
• This PR is a breaking change (e.g. methods or parameters removed/renamed).
• This PR is not a code change (e.g. documentation, README, typehinting, examples, ...).

Checklist

• I have searched the open pull requests for duplicates.
• If code changes were made then they have been tested.
  • I have updated the documentation to reflect the changes.
• If type: ignore comments were used, a comment is also left explaining why.