GrumPHP Mahara for linting on commits

[Doris Tam]

Currently pulls in our phpstan.neon file and runs phpstan on

`git commit` related commands.

Refer to https://github.com/phpro/grumphp

Quick start:

- composer require --dev phpro/grumphp
- composer require --dev phpstan/phpstan

In case SimpleSAMLPHP throws phpstan errors: run `make ssphp`

[Mahara Bot (dev-mahara)]

Patch for "main" branch: https://reviews.mahara.org/c/mahara/+/13668

[Mahara Bot (dev-mahara)]

Patch for "main" branch: https://reviews.mahara.org/c/mahara/+/13830

[Mahara Bot (dev-mahara)]

Reviewed: https://reviews.mahara.org/c/mahara/+/13668
Committed: https://git.mahara.org/mahara/mahara/commit/7c1df258261cf34e6eadd00869d6b5f69173c5f3
Submitter: "Robert Lyon <email address hidden>"
Branch: main

commit 7c1df258261cf34e6eadd00869d6b5f69173c5f3
Author: Doris Tam <email address hidden>
Date: Fri Jan 27 15:35:13 2023 +1300

Bug 2003990: GrumPHP experimental

Currently pulls in our phpstan.neon file and runs phpstan on
`git commit` related commands.

Refer to https://github.com/phpro/grumphp

Quick start:

- composer require --dev phpro/grumphp
- composer require --dev phpstan/phpstan

In case SimpleSAMLPHP throws phpstan errors

Run... make ssphp

Make changes, git add them, git commit

Change-Id: Ifaae01b49d9c5e1d89aaf6f90dea02e74bb317b6

[Mahara Bot (dev-mahara)]

Reviewed: https://reviews.mahara.org/c/mahara/+/13830
Committed: https://git.mahara.org/mahara/mahara/commit/096381df4c4c96cb586547e80acc601044619f29
Submitter: "Robert Lyon <email address hidden>"
Branch: main

commit 096381df4c4c96cb586547e80acc601044619f29
Author: Gold <email address hidden>
Date: Mon Feb 27 10:41:22 2023 +1300

Bug 2003990: GrumPHP v2

Adds the current change id commit hook to the commit message that
GrumPHP over writes. The presence of a change id on this commit message
is the actual test.

Signed-off-by: Gold <email address hidden>
Change-Id: I4e5fbc11914a6d5886a197b6f14295688eb73e9b

[Mahara Bot (dev-mahara)]

Patch for "main" branch: https://reviews.mahara.org/c/mahara/+/13833

[Mahara Bot (dev-mahara)]

Reviewed: https://reviews.mahara.org/c/mahara/+/13833
Committed: https://git.mahara.org/mahara/mahara/commit/93b46f59670e763e71f141dd65a9e17d02ef3799
Submitter: "Doris Tam <email address hidden>"
Branch: main

commit 93b46f59670e763e71f141dd65a9e17d02ef3799
Author: Doris Tam <email address hidden>
Date: Wed Mar 1 12:52:26 2023 +1300

Bug 2003990: GrumPHP custom banners

Change-Id: Ib33aa580cab0ab0f169542ce1437eaf794da2627