Remove add_unique_random_streams and ensemble.add_random_streams. Mypy fixes.

[jlnav]

• Remove add_unique_random_streams and ensemble.add_random_streams.
• Add tools.get_rng to make it the gen's responsibility to initialize random streams.
• This function can still base the seed on workerID.
• Many instantiations of persis_info removed in tests. Kept around where necessary to reset num_active_gens or other data.
• Many mypy fixes.

[codecov]

Codecov Report

❌ Patch coverage is 91.30435% with 12 lines in your changes missing coverage. Please review.
✅ Project coverage is 91.83%. Comparing base (92d032e) to head (089ea5e).
⚠️ Report is 20 commits behind head on develop.

Files with missing lines	Patch %	Lines
libensemble/logger.py	55.55%	3 Missing and 1 partial ⚠️
libensemble/gen_funcs/sampling.py	94.28%	1 Missing and 1 partial ⚠️
libensemble/libE.py	50.00%	1 Missing and 1 partial ⚠️
libensemble/tools/tools.py	71.42%	1 Missing and 1 partial ⚠️
...ble/alloc_funcs/start_persistent_local_opt_gens.py	66.66%	0 Missing and 1 partial ⚠️
libensemble/ensemble.py	83.33%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##           develop    #1710       +/-   ##
============================================
+ Coverage    78.06%   91.83%   +13.76%     
============================================
  Files           81       81               
  Lines         8210     8251       +41     
  Branches      1259     1268        +9     
============================================
+ Hits          6409     7577     +1168     
+ Misses        1561      472     -1089     
+ Partials       240      202       -38     

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

🚀 New features to boost your workflow:

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