Remove git-hooks so app can be installed with "composer create-project" without being a git repository

Some config keys changed as well since the last update

This reverts commit 2535de6a.

While it's not stricly required by everyone it doesn't require any
extra implementation right now and is required by all frontend apps
in the future, so including it should make the initial setup easier.

It gets called during composer install which we need when deploying
without dev packages.

Disabling scripts would work, but then the symfony install commands
would be skipped too...

This mainly means the keycloak config moves to a separate bundle

The core bundle is now available on packagist