SOLR-16406: Take SOLR_MODULES into account

[thomaswoeckinger]

https://issues.apache.org/jira/browse/SOLR-16406

Description

SOLR_MODULES (provided by solr.in.sh) is currently ignored.

Solution

Take SOLR_MODULES into account by changing solr and solr.cmd scripts

Tests

Added to /opt/solr/bin/solr and /opt/solr/bin/solr.in.sh locally and start the server

Checklist

Please review the following and check all that apply:

• I have reviewed the guidelines for How to Contribute and my code conforms to the standards described there to the best of my ability.
• I have created a Jira issue and added the issue ID to my pull request title.
• I have given Solr maintainers access to contribute to my PR branch. (optional but recommended)
• I have developed this patch against the main branch.
• I have run ./gradlew check.
• I have added tests for my changes.
• I have added documentation for the Reference Guide

[epugh]

From a "does this fix the problem" view, the changes LGTM.

[janhoy]

@thomaswoeckinger can you add a CHANGES.txt entry for 9.1, under bugfixes, then we can merge.

[janhoy]

Ping @thomaswoeckinger

[thomaswoeckinger]

Sorry for the late response, i will add a entry tomorrow

[thomaswoeckinger]

@janhoy Added CHANGES.txt entry for 9.1