Add support for draft PRs

[omgjlk]

GitHub announced draft Pull Request status. Eventually they will add new fields to pull request listings and GETs to include the draft status, and allow setting a PR as draft when creating one. We'll want to support those things here!

I'll update this issue when the REST APIs are updated.

[omgjlk]

There is now support for seeing draft status in responses to the REST API so I can get started on adding this.

[staticdev]

@omgjlk anything missing on this PR? It is still draft.

[cjschaef]

Isn't the support to create new draft PR's still missing in main? I don't see a process to set draft in data when the request is made to the API.

github3.py/src/github3/repos/repo.py

Lines 1161 to 1205 in 43aa2d6

	def create_pull(
	self, title, base, head, body=None, maintainer_can_modify=None
	):
	"""Create a pull request of ``head`` onto ``base`` branch in this repo.
	:param str title:
	(required)
	:param str base:
	(required), e.g., 'master'
	:param str head:
	(required), e.g., 'username:branch'
	:param str body:
	(optional), markdown formatted description
	:param bool maintainer_can_modify:
	(optional), Indicates whether a maintainer is allowed to modify the
	pull request or not.
	:returns:
	the created pull request
	:rtype:
	:class:`~github3.pulls.ShortPullRequest`
	"""
	data = {"title": title, "body": body, "base": base, "head": head}
	if maintainer_can_modify is not None:
	data["maintainer_can_modify"] = maintainer_can_modify
	return self._create_pull(data)
	@decorators.requires_auth
	def create_pull_from_issue(self, issue, base, head):
	"""Create a pull request from issue #``issue``.
	:param int issue:
	(required), issue number
	:param str base:
	(required), e.g., 'master'
	:param str head:
	(required), e.g., 'username:branch'
	:returns:
	the created pull request
	:rtype:
	:class:`~github3.pulls.ShortPullRequest`
	"""
	if int(issue) > 0:
	data = {"issue": issue, "base": base, "head": head}
	return self._create_pull(data)
	return None

Supported in Github API's via draft
https://docs.github.com/en/rest/pulls/pulls?apiVersion=2022-11-28#create-a-pull-request