feat(perf): Separate two configurable warmups

feat(perf): Separate two configurable warmups

+ First starts disabled, low-rate, to avoid flooding in some labs.
+ Second starts enabled, max-rate, to avoid unsent packets by TRex.
 + The one in MLRsearch Python library is no longer used.
+ Both warmups are called directly, as they apply also to non-VPP DUTs.
 - Hoststack traffic is not covered yet.
- Not deleting infra-warmup action yet, downstream may be using it.

Change-Id: I72036d0dec5e8e94f5e7cec4692e4ebb07b1ec69
Signed-off-by: Vratko Polak <[email protected]>