chainsync safe closeout

[dpaiton]

Chainsync uses calc_close_* for estimating closeout value, which could fail if the pool is in a situation where positions cannot be closed. We ware working on a general solution for this here: delvtech/hyperdrive-rs#153

This PR is a temporary solution that approximates the closeout value using spot price.

[codecov]

Codecov Report

Attention: Patch coverage is 93.33333% with 1 line in your changes missing coverage. Please review.

Project coverage is 81.55%. Comparing base (9062a60) to head (66d101a).
Report is 82 commits behind head on main.

Files with missing lines	Patch %	Lines
...c/agent0/chainsync/analysis/calc_position_value.py	93.33%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1616      +/-   ##
==========================================
+ Coverage   81.52%   81.55%   +0.03%     
==========================================
  Files          98       98              
  Lines        7263     7265       +2     
==========================================
+ Hits         5921     5925       +4     
+ Misses       1342     1340       -2     

Flag	Coverage Δ
unittests	81.55% <93.33%> (+0.03%)	⬆️

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[slundqui]

LGTM, but this is assuming the equation itself is correct in estimating PNL.