Added regex extraction and drilldown support

[Kranthi-grafana-user]

Added Regex extraction support, using which user can extraction some portion of the legend's text/label

Added drill down feature URL

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
0 out of 2 committers have signed the CLA.

❌ Kranthi_Tatikonda_LDDS
❌ Kranthi-grafana-user

---

Kranthi_Tatikonda_LDDS seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}