[k6] Align tests with updated requirements

[k6] Align tests with updated requirements

- Test load increased to 5 CM handle searches and 5 Id searches to
  reflect current requirements.
- CM handles searches now use a combined search filter including
  1 module and 1 public property, so we are testing with a heavier
  load than required, for early warning of trouble.
- Test load reduced for passthrough operations to 4 VUs per operation
  to reflect addition of batch operation.
- Added test of passthrough write operation with alternate ID.
- Additional refactoring.

Issue-ID: CPS-2349
Signed-off-by: danielhanrahan <daniel.hanrahan@est.tech>
Change-Id: I88d2fe431f74821e8e0e976441efcf82aa320849