CiscoDNA IPAM Driver cannot delete pools

[techpriest002]

Deleting IP pools (IP4Blocks) using the CiscoDNA IPAM driver appears to be broken due to the specification of pool including the slash "/" character, causing the route matching mechanism of Flask to fail.

Steps to reproduce

1. Create Gateway installation running 21.8.1
2. Attempt to delete a block using HTTP DELETE /ipam/pool/:view/:poolcidr where poolcidr is any block containing a forward slash, e.g. "172.16.16.0/20"

Current behavior

Because the path to any pool looks like another URL segment, for example the "/20" portion above, Flask does not find a matching route. This results in a HTTP 404 not found error with the following payload:

{
    "code": 404,
    "description": "The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again.",
    "status": "Not Found"
}

In short, this endpoint can never delete a pool because the specification of a pool and mask creates an incompatible URL path.

Expected behavior

The "delete pool" API endpoint /ipam/pool/:view/:poolcidr needs to be modified to properly parse URLs that contain the additional forward clash included in the CIDR notation.