Display last MOTD from DB under the login form

[valyo]

Display the latest message of the day in the web
Also fixes DDS-1304

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Checklist:

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• Any dependent changes have been merged and published in downstream modules
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• Changes to the database schema: A new migration is included in the PR

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[codecov]

Codecov Report

Merging #1196 (3547144) into dev (1b4f0d8) will decrease coverage by 0.01%.
The diff coverage is 80.00%.

@@            Coverage Diff             @@
##              dev    #1196      +/-   ##
==========================================
- Coverage   85.90%   85.89%   -0.02%     
==========================================
  Files          30       30              
  Lines        3732     3735       +3     
==========================================
+ Hits         3206     3208       +2     
- Misses        526      527       +1     

Impacted Files	Coverage Δ
dds_web/api/superadmin_only.py	69.69% <0.00%> (-2.18%)	⬇️
dds_web/web/root.py	89.47% <100.00%> (+1.23%)	⬆️

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[i-oden]

Could you add the following lone to the end of the MOTD endpoint?

return {"message": "The MOTD was successfully added to the database."}

[i-oden]

Looks good and works.

Information for our future selves: We decided during the morning meeting that we will merge it like this so that we have the information there, and then we'll possibly change this if we come up with a better way to display it.