Issue on AJAX submits

Problem/Motivation

I have faced an issue with AJAX submits, during this process I see that if I have some view exposed forms on the LB pages, and during the AJAX filtering the module loses the connection to Lthe B theme and instead of the LB theme it uses non-LB, it was causing some wrong templates to be associated with the page.

Steps to reproduce

1. Create the LB page with an exposed form on it
2. Use AJAX submitting
3. Use a filter and check that the theme is now not the LB one

Proposed resolution

I propose to extend the LayoutBuilderThemeNegotiator functionality similar to the one we have in AjaxBasePageNegotiator