fix: fix Qmax update after load new parsed data

[stevenhua0320]

@sbillinge ready to review. Note that the logic here is pretty the same as before, but the difference is that in the process of loading the metadata, we need to update it right after we load it so that Qmax could be updated. And then we do the self._flush to dump other parameters into the Profile. Since we might need to use it internally multiple times, I made a private function for this. I also did a test on the local for what we can test here #59. Using the script that provided, I confirmed that Qmax is indeed updated when we loadParsedData again.
Closes #59

diffpy.srfit_env) huarundong@Stevens-MacBook-Pro-405 diffpy.srfit % python check_qmax_reload.py test_1.txt test_2.txt
/Users/huarundong/dbs/diffpy.srfit/check_qmax_reload.py:94: DeprecationWarning: 'diffpy.srfit.fitbase.FitContribution.setProfile' is deprecated and will be removed in version 4.0.0. Please use 'diffpy.srfit.fitbase.FitContribution.set_profile' instead.
  contribution.setProfile(profile, xname="r")

Initial generator Q_max from test_1.txt: 25.0

Metadata in new file suggests Q_max should be 40.0, q_max is now 40.0

These are equal

Now setting Qmax manually from the second file metadata...

Metadata in new file suggests Q_max should be 40.0, q_max is now 40.0

These are equal

Result: Qmax already updates on profile reload.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 69.36%. Comparing base (1e60597) to head (e2b5c46).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #173   +/-   ##
=======================================
  Coverage   69.36%   69.36%           
=======================================
  Files          25       25           
  Lines        3457     3457           
=======================================
  Hits         2398     2398           
  Misses       1059     1059           

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[sbillinge]

one naming suggestion

[sbillinge]

Let's call this _on_profile_update maybe?

[sbillinge]

yeh, thans for this @stevenhua0320 .... we finally fixed @rjkoch's bug from 2019!