pfm(e2e): test are slow and flakey, try CometMock

[Reecepbcups]

Issue

Because of the number of docker network nodes setup:

• Interchaintest with PFM is flakey (github network limitation)
• PFM test are slow (IBC + single core for multiple networks + relayer)

Solution

Interchaintest added cometmock support earlier in the year here. We should see if using it allows for nearly instant block times.

This way test are drastically faster & if they do fail, it should be 1-2m instead of ~5-6m

Implementation note

NOTE: relayer will need to have a faster min-loop-duration to keep up.