Automatic merge from submit-queue (batch tested with PRs 50103, 49677, 49449, 43586, 48969)
Adding IPv6 to cidr_set and cidr_set_test
**What this PR does / why we need it**:
This allows IPv6 in cidr_set
Currently cidr_set only supports IPv4. This adds IPv6 compatibility and adds
IPv6 unit tests.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes#43588
**Special notes for your reviewer**:
The IPv6 code here makes some assumptions.
The subnets should be at least /64. (maximum 64 bits of prefix)
The subnet mask size cannot be greater than 30 more than the cluster mask size.
**Release note**:
```release-note
```
063fc6a73a