userblacklist: added missing kemi functions

[fsantulli]

Pre-Submission Checklist

• Commit message has the format required by CONTRIBUTING guide
• Commits are split per component (core, individual modules, libs, utils, ...)
• Each component has a single commit (if not, squash them into one commit)
• No commits to README files for modules (changes must be done to docbook files
  in doc/ subfolder, the README file is autogenerated)

Type Of Change

• Small bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds new functionality)
• Breaking change (fix or feature that would change existing functionality)

Checklist:

• PR should be backported to stable branches
• Tested changes locally
• Related to issue #XXXX (replace XXXX with an open issue number)

Description

• added three new kemi functions allowing to call the missing check_blacklist (global or custom) and check_whitelist functions;
• fixed dynamic sources loading when adding sources within the script calls;
• fixed match_mode in check_whitelist function as it was just numeric before.

[miconda]

Thanks for the contribution! The commit message should be formatted according to the contributing guide:

• https://github.com/kamailio/kamailio/blob/master/.github/CONTRIBUTING.md#commit-message-rules

You actually did the pull request title and comments like the commit message should have been.

This PR can be eventually merged manually with the proper commit message format, but have it in mind for future contributions.

I have also some comment to the code of the commit, otherwise maybe @henningw or @lbalaceanu would like to review before merging.

[henningw]

No action necessary from your side. :-) I will also have a look later today and merge it when I did not notice anything else.

[henningw]

Pull request merged manually (to adapt the commit logs). This changed code in different areas , so I decided to not backport it to stable branches right now. After some testing it could be backported to 5.3 stable branch, though.