Apply Registered `GeneralRegex` sanitizers to `Variables` before storage

A bunch of the commandtests in microsoft/mcp actually end up needing to store a full id.

It'll look something like this if we don't sanitize:

```
"Variables": {
"amlfsSubnetSmallId": "/subscriptions//resourceGroups//providers/Microsoft.Network/virtualNetworks/lustrerecord-vnet/subnets/amlfs-small",
"Location": "westus"
}
```

and the like. This is likely a breaking change to new recordings in certain circumstances for the azure-sdk-for-net repo, so this will be an option on `Record/StopRecording`

Start at the Record/StopRecording entry points and trace how Variables are stored and how registered GeneralRegex sanitizers are applied. Confirm how the option should affect new recordings and verify that full resource IDs are sanitized before storage without changing behavior when the option is disabled.

Written by the indexing model from the issue text.