Remove all flask search references in favour of RTD

[aaryanporwal]

Done

• Upgraded webteam.flask-base version
• Removed webteam.search and webteam.discourse module since we moved to read the docs in #350
• Removed all unused markup, styles and python functions for search.

QA

• Check out the demo site: https://anbox-cloud-io-355.demos.haus/
• Check if search works well and you're redirected to documentation.u.c.
• Check if anything is unexpected related to search.

Issue / Card

Fixes WD-15028

[webteam-app]

Demo

Jenkins

demos.haus

[aaryanporwal]

Fixed the build, set a new secret-key in demo k8s cluster. Please check the demo build.