introduce intrinsic constant tuple DEFAULT_ODE_SOLVER_OPTIONS

[ytdHuang]

The default keyword arguments for ODE solvers are:

• abstol = 1e-8
• reltol = 1e-6
• save_everystep = false : this can avoid storing all the internal states in sol.u if users set saveat = []
• save_end = true

This PR also add some runtests for sesolve and mesolve.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 93.21%. Comparing base (c5da8e2) to head (248f872).

❗ Current head 248f872 differs from pull request most recent head 582bbf9

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Additional details and impacted files

@@            Coverage Diff             @@
##             main     #172      +/-   ##
==========================================
- Coverage   93.22%   93.21%   -0.01%     
==========================================
  Files          28       28              
  Lines        2051     2049       -2     
==========================================
- Hits         1912     1910       -2     
  Misses        139      139              

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