Cleanup unwanted files

[vidriduch]

We have found unwanted files commited to this repository:

• .idea
• .idea/.gitignore
• .idea/github-actions.iml
• .idea/modules.xml
• .idea/php.xml
• .idea/vcs.xml

These files, present many issues as various build manifests can contain secrets (generated during build time) or unwanted images/files from template repositories can be copied to container images, which slows build time, etc.
We also decided not to support .idea settings, if they are present.

Please, remove above mentioned files and make necessary adjustments to .gitignore and .dockerignore so these will not be commited and used again.
Also, check if there aren't any more files that we might have missed that are unnecessary or unwanted and can be removed.