docs: Complete the "Other endpoints" documentation

[JavierMtzRdz]

addresses issue(s) #1517, #1209, #1518, #1520, #1670

Summary:

This PR updates the documentation for the “Other endpoints", superseding the corresponding changes made in #1697.

• Updated "Other Endpoints" headers to be consistent with Epiportal (partially fixed Change format of other endpoints' doc pages to be like the covidcast endpoints #1517).
• Marked Flusurv as active.
• Verified/updated reporting cadence and temporal scope for: fluview_clinical, youtube-survey, safegraph, and wiki.
• Included the last dates available (fixed Update docs for inactive signals to include last dates available #1670)
• Added Estimation, Backfilling, and Limitations sections for fluview and flusurv (partially fixed Change format of other endpoints' doc pages to be like the covidcast endpoints #1517).
• Added missing parameters, valid input lists, and response definitions for various endpoints (partially fixed Change format of other endpoints' doc pages to be like the covidcast endpoints #1517, fixed Document usage instructions for NoroSTAT #1209 and partially fixed List and describe field names in other endpoint return values #1518).
• Removed duplicated paragraph in nidss_dengue and fixed various broken links.
• Refreshed code samples for all "Other Endpoints" to use the latest client versions (fixed Add code examples to other endpoint pages (and maybe also covidcast pages?) #1520)
• Restructured inactive sources into dedicated subsections under their respective parents.

Prerequisites:

• Unless it is a documentation hotfix it should be merged against the dev branch
• Branch is up-to-date with the branch to be merged with, i.e. dev
• Build is successful
• Code is cleaned up and formatted

[nmdefries]

Want more detailed info for some of these. Overall structure, headers, etc look good. I made some small wording changes, will push those in a minute.

[JavierMtzRdz]

I have addressed most of the comments, except for the one regarding the commented licenses. This involves specific changes as well as added context and details.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[JavierMtzRdz]

I've uncommented the licenses as discussed. Additionally, I included a link to Quidel under the main endpoint regarding limitations, etc.