Booster Map matching deficiency

[jberthold]

During an analysis of a reported simplification issue in slack, the simplification log showed that booster was unable to match a singleton (key |-> value):Map with a pattern (K |-> _V) M:Map.

• Create a small example that demonstrates the issue
• Inspect the internalised terms for the subject and pattern
• improve matching code for internalised KMap to be able to match this (using M == .Map)