[VT]: add a numeric value tracker and updater for working sets of a VT client

[GwnDaan]

This is the first of several PR's to address #403, this one adds the fundamentals, as well as the tracking and updating of numeric values.

[sonarcloud[bot]]

Quality Gate passed

The SonarCloud Quality Gate passed, but some issues were introduced.

32 New issues
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud