Re-work install script
Add new java images and update to labeled java format
Latest version hard coded to 1.18.2 as there is no API to find latest supported MC version
Add check for latest `[[ "${MC_VERSION}" == "latest" ]]`.
Previously, it was only checking for exact versions or empty value, and I completely forgot to test latest.
Resolves#1516
Rewrite the egg to support dev and stable versions, together with newer +1.16 installers.
Does not rely on their own API latest fetching, because it picks latest Github release that can include old pre-releases.