Include Infrastructure team labels in group label checks

We have two team labels for teams in Infrastructure with backend engineers:

1. teamDelivery
2. ~"team::Scalability"

Many policies don't work well with these labels, in some cases (like gitlab-org/build/CNG!418 (merged)) applying a group label in addition to the team label.

This MR has three commits:

1. Rename the existing 'team labels' concept to 'deprecated team labels' as this refers to labels like Create [DEPRECATED].
2. Add a new #has_infrastructure_team_label? method to avoid introducing new ambiguity (i.e. never refer to just 'team labels' but either 'deprecated team labels' or 'infrastructure team labels').
3. Use #has_infrastructure_team_label? in whichever policies were using #has_group_label? already.

Closes #448 (closed).