feat(semantic_search): extend register_search, add endpoint_name

[DangerousWizardry]

Add the ability for users to name the register_search endpoint in order to have multiple search element on the same page.

Description

Add the possibility for developper to name the shiny endpoint generated by registerDataObj so that user can have multiple search input pointing to different endpoints

Definition of Done

• The change is thoroughly documented.
• The CI passes (R CMD check, linter, unit tests, spelling).
• Any generated files have been updated (e.g. .Rd files with roxygen2::roxygenise())