Use WaitForCondition in channel upgrade tests

[damiannolan]

In channel upgrades e2e tests we commit to send packets and begin a channel upgrades which in turn then flushes the packets, completing their lifecycle.

We then wait for some arbitrary number of blocks before querying the channel version - asserting that it has been updated after the relayer finishes the channel upgrade.

It would be more robust to use test.WaitForCondition rather than waiting arbitrary number of blocks for proceeding.

See diff and PR comments below.

Num block waited was bumped here. Without this there was an error surfacing on L129 - when querying the channel version it was not fee enabled.

This must be some latency added somewhere in tx flow from the relayer trying to complete the channel upgrade. First it flushes packets and then makes this query against channel version to ensure the upgrade has completed.

Note, this could probably be changed to use test.WaitForCondition or something similar

Originally posted by @damiannolan in #7261 (comment)

[NisTun]

Can I handle this test @damiannolan ?