[DMX-5787][DMX-5788] Search resultant linked pages should not redirect to github.io

[jl4ever]

JIRA: https://procoretech.atlassian.net/browse/DMX-5787

Summary

This changeset is to help address the issue of having search result documentation pages in the iframe link back to github.io origin.

The changes are:

1. Only sets when not in an iframe, so iframed pages navigate within the iframe instead of breaking out.
2. Navigation links: Changed from relative URLs to absolute URLs using interpolated conditionals
3. Gets the parent window's origin (ex: localhost:3000 or developers.procore.com) from ancestorOrigins or document.referrer so that there is no unfocused nav away into github.io source
4. Rewrites navigation and content links to show the parent origin (localhost:3000 or developers.procore.com) on hover.
5. Added rewriteSearchResultLinks() to rewrite search result links.
   a. use observer to add and rewrite search result links
   b. make sure navigation is always within the bound of the iframe for the search result rewritten links

Testing output from locally running dev-portal

• Searched for a topic, highlighted url shows localhost:3000 [local dev-portal] (not localhost:4000 <-- running jekyll server)

• Clicked on the link and it navigates to the right documentation page

[m-graf]

Loooks good!!