Port OPC changes to NG7

[Thodor12]

Identical in core changes to #13

Few differences:

• Version format is "${major}.${minor}.${patch}-${{ inputs.suffix }}" as discussed in Discord, no MC version
• MC version is returned as part of the job outputs
• New tasks in mod.gradle: getProjectName, used to return the rootProject.name so the customCurseFileName can be set properly
• (Temporary) A test task so I can verify in the build CI the version expected curse artifact name is as we expect it to be, because release can't be manually tested, will be removed before merge