Updating set-version.sh and adding set-server-version.sh. Updated server version to 26.0.7

[mposolda]

closes #639

• Updated set-version.sh script to update only project version, but not version of keycloak server

• Introduced set-server-version.sh script, which is used to update all the references to keycloak server, but does not update project version. I am planning to run this script from keycloak-rel during keycloak server release as during server release, we are not updating anymore the project version, but we need to update "keycloak server version" .

• Small adjustements needed in the sed commands as the string $$VERSION$$ may not be available anymore in the kubernetes.yml and openshift.yml files. It would be needed to be able to replace also something like version: 26.0.7 with something like version: 26.0.8, which was not supported by previous sed scripts, which assume string $$VERSION$$

• Updated server version to last released 26.0.7 used separate commit for that to not mix with updated bash scripts. (Hopefully in the future, this will be always done automatically in the quickstarts main branch for further keycloak server releases.)

[graziang]

@mposolda Thanks, LGTM!

[mposolda]

@graziang Thanks!