[5pt] Ensure all outputs from alpha testing change files to full read/write/exec

[RobHanna-NOAA]

In various recent testing, against synthesize_test_cases.py, some of the outputs were in read only mode. Changing the output files to be read/write/exec will have some value.

Especially execute to csv as it allows Libre to open the csv's without permissions issues. When trying to open csv's with Libre even on your own EC2 / EBS, it fails with a permissions issue as it needs execute (not just r/w). It remains to be seen if this also fixes the permissions issues with Libre on the EFS drives.

It is a pretty quick fix, really just a couple of lines of code but it does have value.

And we might as well do the same for eval_plots outputs.

PS: Low effort, high value