fix key error after reload

Description

When the application was reloaded (and therefore the active_runs dict is cleared) we failed on most operations (back, add, plot etc.). We can easily fix that by adding the current run to the active_runs when necessary in every operation.

This change won't be affecting users a lot but we get a nicer development experience.

Changes

In the runs/views.py for most operation we added handling for empty active_runs.

Testing

Go through a worklow in PROTzilla, trigger an application reload, check that operations are working without failing.

PR checklist

Development

[x] If necessary, I have updated the documentation (README, docstrings, etc.)
[x] If necessary, I have created / updated tests.

Mergeability

[x] main-branch has been merged into local branch to resolve conflicts
[x] The tests and linter have passed AFTER local merge
[x] The code has been formatted with black

Code review

[x] I have self-reviewed my code.
[ ] At least one other developer reviewed and approved the changes

File	Statements	Missing	Coverage	Coverage (new stmts)	Lines missing
protzilla/data_analysis
ptm_analysis.py
protzilla/data_preprocessing
filter_proteins.py
outlier_detection.py
peptide_filter.py
transformation.py
protzilla/importing
peptide_import.py
protzilla/methods
data_analysis.py					631-641
data_preprocessing.py
importing.py					142
ui/runs
views.py					22, 245-246, 268-269, 290-291, 362-363, 384-385, 405-406, 442-443, 463-464, 478-479, 605-606, 629-630
ui/runs/forms
data_analysis.py					926-934, 962
Project Total

cschlaffner / PROTzilla2