fix: Check embed for "new search" and dedicated landing pages

[darcywong00]

Follows the page_root pattern in #734 for the "New Search" link.
For Keyman 14.0-18.0 apps using the embedded view, we don't include the locale for "Near Search"

Also added a section in .htaccess so dedicated landing pages can check the embed session cookie.
Fortunately, all the landing pages are index.php.

Test-bot: skip

[keymanapp-test-bot]

User Test Results

Test specification and instructions

User tests are not required

[mcdurdin]

LGTM, I am not sure how the /h/ pages slipped through because I did test those...

[darcywong00]

LGTM, I am not sure how the /h/ pages slipped through because I did test those...

hmm, current staging site (before I merge this)

Starting at
https://keyman-staging.com/go/android/14.0/download-keyboards?q=ipa

redirects and settles on https://keyman-staging.com/keyboards/?q=ipa in an embedded search with the cookie embed_keyboards_no_locale_redirect set.

Clicking the top link (landing page to /ipa) goes to

https://keyman-staging.com/en/keyboards/h/ipa/?embed=android&version=10.0.0.0
still embedded view and has 2 cookies

Name	Path
embed_keyboards_no_locale_redirect	/
embed_keyboards_no_locale_redirect	/en/keyboards/h/ipa

[mcdurdin]

Ah I think we need to set the path of the cookie!

[mcdurdin]

    setcookie('embed_keyboards_no_locale_redirect','1',0, '/');

[mcdurdin]

It is important to add the path for the cookie as shown above, but we still need your patch as well. I'll add the cookie as a separate PR