Add missing Project, CreateProjectOptions and EditProjectOptions fields

[turnabout]

Hello!

I found some missing fields on the main project-related structs (Project, CreateProjectOptions, EditProjectOptions). I took the liberty to add them where they're needed (in accordance with the GitLab API documentation https://docs.gitlab.com/ee/api/projects.html).

Here is a list of every missing field I found, as well as the structs I found were requiring them.

FIELD	TYPE	STRUCTS	DESCRIPTION
analytics_access_level	string	Project, CreateProjectOptions, EditProjectOptions	One of disabled, private or enabled
keep_latest_artifact	boolean	Project, EditProjectOptions	Disable or enable the ability to keep the latest artifact for this project.
merge_pipelines_enabled	boolean	Project, CreateProjectOptions, EditProjectOptions	Enable or disable merge pipelines.
merge_trains_enabled	boolean	Project, CreateProjectOptions, EditProjectOptions	Enable or disable merge trains.
restrict_user_defined_variables	boolean	Project, EditProjectOptions	Allow only users with the Maintainer role to pass user-defined variables when triggering a pipeline. For example when the pipeline is triggered in the UI, with the API, or by a trigger token.
merge_commit_template	string	Project, CreateProjectOptions, EditProjectOptions	Template used to create merge commit message in merge requests. (Introduced in GitLab 14.5.)
squash_commit_template	string	Project, CreateProjectOptions, EditProjectOptions	Template used to create squash commit message in merge requests. (Introduced in GitLab 14.6.)

Additionally, the struct tags for the ShowDefaultAwardEmojis field on CreateProjectOptions and EditProjectOptions were misspelled, so I fixed those.

[svanharmelen]

Thanks @turnabout! LGTM 👍🏻

[neiser]

@svanharmelen As it's merged, would you mind releasing it as well? I'd appreciate it :)