feat: add `get_hydrometrie_observations_tr`

Fix #7
2 jobs for master in 59 seconds (queued for 4 seconds)
Status Name Job ID Coverage
  Check
failed check #192548
docker

00:00:59

 
  Website
skipped website #192549
docker
 
Name Stage Failure
failed
check Check
❯ checking dependencies in R code ... NOTE
Namespace in Imports field not imported from: ‘config’
All declared Imports should be used.

0 errors ✔ | 1 warning ✖ | 2 notes ✖
Error: R CMD check found WARNINGs
Execution halted
Cleaning up file based variables
ERROR: Job failed: exit code 1