SOLR-17533: Rearrange and cleanup solr.cmd

[malliaridis]

https://issues.apache.org/jira/browse/SOLR-17533

Description

By rearranging the code we can allow the java classes to handle more of the argument parsing and remove some more lines from bin/solr.cmd.

Solution

This PR rearranges the code in a way that it is a more "top-to-bottom" flow without many up-and-down jumps via goto. Additionally, it gets rid of unnecessary statements and parsing and forwards all interactions to SolrCLI if it is not one of the commands start, stop or restart. This approach is followed in bin/solr as well.

Tests

We are still lacking on tests for the bin/solr.cmd script. See SOLR-17508.

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, not available for branches on forks living under an organisation)
• 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]

maybe say "auth" too?

[malliaridis]

This part is skipped in case of the auth command. The auth command has its own parsing plus the java class parsing. If I am not mistaken, this was the same behavior before and if I am not mistaken bin/solr does the same. Correct me if I am wrong though.

[epugh]

Yeah, it does.. I think the way in bin/solr it is that first you do everything. Then you do auth. Then you do the remaining ones of start, stop, restart.

[epugh]

LGTM. One nit on the help args... So much cleaner. and I love that it ends up removing 298 lines of code!