maven settings script MAVEN_REPOS prefixes lowercase

In example of MAVEN_MIRRORS there are lowercase with dash prefixes "dev-one,qe-two". This can not work because it is necessary to use prefix in uppercase with underscore when trying to read prefix_MAVEN_MIRROR_URL.

Now it is reading dev-one_MAVEN_MIRROR_URL, but it should read DEV_ONE_MAVEN_MIRROR_URL.

Desired function is introduced in CLOUD-2911: _maven_find_prefixed_env()

Example of MAVEN_MIRRORS:
https://github.com/jboss-openshift/cct_module/blob/master/jboss/container/maven/api/module.yaml

Obsolete usa of _maven_find_env():
https://github.com/jboss-openshift/cct_module/blob/2473cf2117d2487ca1a72ff77306776a44266575/jboss/container/maven/default/bash/artifacts/opt/jboss/container/maven/default/maven.sh#L180

There exists way to avoid this: Use uppercase without dash in MAVEN_MIRRORS (e.g. dev-one -> DEVONE).