refactor(db): return schedule on create and update

[ecrupper]

Continuing effort from these: #861, #882, #884, #913

[codecov]

Codecov Report

Merging #915 (c60f664) into main (439455c) will increase coverage by 0.02%.
The diff coverage is 54.54%.

@@            Coverage Diff             @@
##             main     #915      +/-   ##
==========================================
+ Coverage   71.38%   71.40%   +0.02%     
==========================================
  Files         304      304              
  Lines       12500    12495       -5     
==========================================
- Hits         8923     8922       -1     
+ Misses       3142     3138       -4     
  Partials      435      435              

Files Changed	Coverage Δ
api/schedule/create.go	14.50% <0.00%> (+0.21%)	⬆️
api/schedule/update.go	0.00% <0.00%> (ø)
database/schedule/update.go	84.21% <66.66%> (ø)
database/schedule/create.go	81.25% <80.00%> (-1.11%)	⬇️