Profiler: NumberNamedMessages is not a clear name to describe its function

[becksebenius-unity]

Describe the bug
The profiler counter NumberNamedMessages is ambiguous about whether it is number of named messages received or sent. Users cannot determine this without doing manual testing.

To Reproduce
Steps to reproduce the behavior:

1. Open MLAPI Messages profiler module
2. Observe NumberNamedMessages counter
3. Question your own sanity

Expected behavior
Counters should clearly describe their function

Environment (please complete the following information):

• OS: Win10
• Unity Version: 2020.2.7f1
• MLAPI Version: 0.1.0
• MLAPI Commit: a0e87b3

Additional context
Note - this applies to NumberUnnamedMessages as well
Note - the actual value of the counters is number of named messages received

[will-mearns]

Committed to via MTT-539