Gitlabform

* Don't show "Warning: Using group_shared_with: is deprecated" although the user is not really using this config syntax.

* **Complete support for managing groups and projects members**:
* Add enforcing (direct) project members - groups and users, including being able to remove all direct members and keep only the members inherited from the group. Implements [100](https://github.com/gitlabform/gitlabform/issues/100).
* Unify the configuration syntax for group and project level membership.

✨ **New** ✨ config syntax example:
yaml
projects_and_groups:
foo/*:
below key now includes what used to be under
`group_shared_with` and `enforce_group_members` keys
group_members:
there are only up to 3 direct keys below
groups:
another-group:
below key's name been changed to the name used in projects `members`
for groups (and the same as in the API to share group with group)
group_access: 30
users:
my-user:
access_level: 50 owner
this will enforce group-level users to be ONLY as defined above
enforce: true

this will make the projects in `foo` group not contain any **direct** users or groups other
(so it will make it contain only the ones inherited from the group `foo`)
members:
enforce: true

The 🏚 old and deprecated 🏚 syntax for a similar* config would be:
yaml
projects_and_groups:
foo/*:
group_shared_with:
groups:
another-group:
group_access_level: 30
group_members:
my-user:
access_level: 50 owner
enforce_group_members: true

!!! * - there was no enforce project members support before v2.8.0 !!!

The old syntax works but will generate warnings. Support for it will be removed in one the future major GitLabForm versions.

* Speed up running for `ALL_DEFINED`, when the defined groups and projects for just a small part of all the GitLab instance's groups and projects. Additionally **always** show the number of omitted groups and projects for any reasons (no config, archived, skipped). Fixes [285](https://github.com/gitlabform/gitlabform/issues/285).

* **Allow processing only requested configuration sections** using a new cli argument `-os / --only-sections`.
* Minimize the number of unnecessary audit branch unprotect/protect events. Up to now every apply of the `files` section for protected branch resulted in unprotect and then (re)protect event for each protected branches and each file. Now this will only happen when the user running GitLabForm actually needs to do that, which should not happen often if you are using an admin account. Completely fixes [178](https://github.com/gitlabform/gitlabform/issues/178).

* **Complete support for Protected branches - access levels / users / groups allowed to push/merge/unprotect** (**GitLab Premium (paid) only**). PR [289](https://github.com/gitlabform/gitlabform/pull/289).
* **Add option to allow push force in protected branches**. Implements [227](https://github.com/gitlabform/gitlabform/issues/227).
* Fix a bug causing the app to get HTTP 502 from GitLab when protecting branches in some cases.
* Fix getting members list to include usernames of all direct members not just the first page. PR [284](https://github.com/gitlabform/gitlabform/pull/284).

Big thanks to the contributors of this release: [trissanen](https://github.com/trissanen)

* **Make commit messages for file operations configurable.** Implements [278](https://github.com/gitlabform/gitlabform/issues/278).

Thanks to [aleung](https://github.com/aleung) for his contribution!