should not end pool of base token

It should not be possible to end a pool that is the base token of a chain. Ie, we shouldn't end the BNB pool, while we have a BOLT pool. This would cause the BOLT to be frozen.

We can either use the "gas" memo to send some bnb, so we have something to utilize, or block the last staker from unstaking in the bnb pool??

One way to track which pools should be "protected" is note the assets we observe as "gas" from the observer, and mark those pools as "protected" or "gas pools". Then before we end that pool, we check that there are no other pools of the same chain that do not have the status "PoolSuspended".

make sure adding this feature doesn't break ragnarok