Add invariant checks to fuzz tests

[sentilesdal]

Adds the following checks:

1. PV always >= idle
2. ∆ lp share price should never be more than 0.1%

Part of #1123

[codecov]

Codecov Report

Attention: 6 lines in your changes are missing coverage. Please review.

Comparison is base (0e8f0c7) 80.98% compared to head (27679c5) 80.90%.

Files	Patch %	Lines
...ethpy/ethpy/hyperdrive/interface/read_interface.py	14.28%	6 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1251      +/-   ##
==========================================
- Coverage   80.98%   80.90%   -0.09%     
==========================================
  Files          94       94              
  Lines        5370     5377       +7     
==========================================
+ Hits         4349     4350       +1     
- Misses       1021     1027       +6     

Flag	Coverage Δ
unittests	80.90% <14.28%> (-0.09%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[dpaiton]

awesome!