Max long & short failures in fuzz testing

[dpaiton]

Fuzz testing is seeing the following errors:

• calculate_max_long
  • InsufficientLiquidity: Negative Interest
  • Initial guess in calculate_max_long is insolvent
  • target share reserves less than effective share reserves
• calculate_max_short
  • absolute_max_short is insolvent
  • arithmetic operation overflow

The fuzz pool is initialized to a known-good state (@slundqui is 80% certain it is good based on visual inspection of the parameters from himself, Jonny, & Alex and comparison against rust CI tests).
Random bots make trades and call calc_max_long and calc_max_short at random times throughout.

[dpaiton]

possibly related:
fuzz_calculate_max_short is failing with large differences in budget amount: #121

This is happening rarely, but I believe that is because the test itself is rarely hitting the assert. I rewrote the test to always hit the assert and it fails much more often.

[dpaiton]

Related to #185

[dpaiton]

• This line was recently added in hyperdrive 0.20.1; fix checkpoint exposure bug #207 and should be removed once max long is fixed (because the max should always be solvent):

in test_calculate_max_long

// Ensure max long is valid.
if state.calculate_open_long(max_long).is_err() {
    continue;
}

• These test are being ignored and should be revisited by whoever picks up this project:
  fuzz_sol_solvency_after_short
fuzz_calculate_max_short_budget_consumed

• fuzz_absolute_max_short_valid does not pass 100% of the time due to pool state after preamble not supporting a valid short