chore: consolidate advanced compose stacks into dial-1.x / dial-2.x

[olegmikhnovich]

Description of changes

Consolidate the two advanced full-stack setups (Core, Chat, Admin, Keycloak) into one folder, named by DIAL release line instead of a v1/v2 suffix:

• Merged dial-docker-compose-advanced-v1/ and -v2/ into dial-docker-compose-advanced/ with dial-1.x/ (legacy) and dial-2.x/ (current) subfolders, via git mv so history follows the renames.
• Added a parent README marking 1.x legacy / 2.x current, plus a deprecation banner in the 1.x README. Status lives in the READMEs, so folder names don't need renaming at 3.0.
• Repointed the CI smoke tests in pr.yml / release.yml at the new ci paths and renamed the jobs to run-advanced-{1,2}x-smoke-test.
• Updated the full-stack quick-start tutorial links.

Checklist

• Title of the pull request follows Conventional Commits specification

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