Migration to quarto

[MaximMoinat]

As described in #711, this PR migrates the r markdown to quarto.

Highlights:

• Uses Cosmo (light) theme, and Darkly (dark) theme.
• The navbar does not support nested dropdown as used for cdm v54, now just expanded
• Home page: removed calendar as it was empty since 2023 and moved the cdm schema image up
• Refactorings for cdm specs generation, sql scripts and
• Readd the section headings in cdm specs (Clinical Event Tables, Health Economics, etc.)
• Incorporate a few minor doc fixes from open PRs: fix: correct broken forum URLs across docs and Rmd sources (Fixes #754) #786, Fixed typos/grammar and a missing link in dataModelConventions.html #747, fix: correct broken forum URLs across docs and Rmd sources (Fixes #754) #786, fix: upgrade HTTP links to HTTPS in Rmd source and generated HTML docs (Fixes #790) #791
• Removed the 'oncology extension' page (was not linked from anywhere) and the associated csv's describing the episode tables. These are now part of v5.4 and should be maintained there. Redundant oncology documentation page  #514

Preview for review: https://maximmoinat.github.io/CommonDataModel/

[clairblacketer]

Thank you for putting this together @MaximMoinat ! Reviewing now

[clairblacketer]

I am checking this PR using this link: https://maximmoinat.github.io/CommonDataModel/ and overall it looks great! Quarto works well and everything migrated over.

A couple of things I notice that we can fix after this quarto migration (I will move these to an issue):

• check marks and Xs on front page need to be updated, right now they look like r cde
• link to annual symposia on background page to be updated
• update dates on the cdm refresh process page
• update CDM WG meeting information
• Remove links to google drive location on refresh process page
• Remove link to running agenda on refresh process page
• all links in documentation need to be moved to the CDM v5.5 pages when available
• A good task for 2027 would be to review all old documentation (from 2021) to make sure it still holds up and we agree with the message
  - For example the patient privacy article heavily refers to HIPAA, we need to add EHDS as well
• Patient privacy page references are in bibtext format, we need to figure out how to update these for quarto
• Custom concepts page - I think there is a poster from Roger we might need to add in there as reference
• Check marks on the CDM v5.5 page work, we can take the logic from there for the front page
• The second and third columns in the CDM table descriptions need to be widened to accommodate the text better
• tooling support page needs correct emojis and all tables included
• CDM additions - accepted changes needs either to be removed or a correct link
• update era table scripts (issue already open for this)

[clairblacketer]

I added some comments in issue #797 just with some things I observed but overall the mechanics for quarto are working well so I am approving and we can pull this in.