Store both times and times_states in time evolution solutions

[ytdHuang]

Checklist

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Description

In this PR, we store both times and times_states in time evolution solutions.

Here are the new definitions:

• times: List of time points which is same as user-specified tlist (corresponding to sol.expect)
• times_states: List of time points which is same as SciML sol.t (corresponding to sol.states)

Related issues or PRs

fix #504

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.05%. Comparing base (3057e3e) to head (d0bb36d).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #506   +/-   ##
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  Coverage   94.05%   94.05%           
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  Files          51       51           
  Lines        3513     3513           
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  Hits         3304     3304           
  Misses        209      209           

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