Need a warning to the user when exporting workbook if a gene does not have a degradation/production rate

[kdahlquist]

We discovered today that when a user exports data to an Excel workbook with degradation rate and prodution rate sheets, a gene will be missing from those sheets if there is no value for the degradation rate/production rate. It took us a while to figure out why GRNmap wouldn't run. We need to remedy this in two ways:

1. Give a warning to the user upon export that says: " does not have a degradation rate in our database. A degradation rate will need to be supplied to run this workbook in GRNmap." and/or " does not have a production rate in our database. A production rate will need to be supplied to run this workbook in GRNmap."
2. The gene ID needs to included in the degradation_rates and production_rates sheets, but without a value.

I am going to look into a couple more tweaks for this that will take some additional time:

1. I'm going to try to find a longer list of degradation rates/production rates so that this is less likely to happen in the future.
2. We may end up providing a replacement value (instead of null), if it is missing from our database. We would then maybe need to have some logic where the user is asked whether they want to use the replacement value.

[dondi]

Because this involves export code, @Amelie1253 and @MilkaZek have been assigned for coordination, with @ntran18 taking the lead

The database part though is definitely in @ntran18’s wheelhouse

[ntran18]

I added a PR #1195 for code review

[dondi]

May be a follow-up after resolution of #1120, #1164, #1165