Update header on MUR search that links to EQS from search results page

[AmyKort]

Now that we've added archived MURs to the MUR search, we should update the "feature in progress" alert that shows above search results. Currently, if a user were to search for an 1977 MUR, the feature in progress alert would still provide a link to EQS as an alternative search option. See for example, https://www.fec.gov/data/legal/search/enforcement/?search_type=murs&search=&mur_no=400&mur_respondents=

[dorothyyeager]

We are going to update the AO search in progress boxes along the same lines as well.

Completion criteria:

• [x] Draft language for updating AO and MUR search in progress boxes
• [x] Update the MUR and AO "work in progress" banners on specific pages (work with @patphongs)

[dorothyyeager]

The wording agreed upon is here: https://docs.google.com/document/d/1k9DVgHSoYv8voP0uDSX-EwniFSGyP-caCPAUbtwjPmI/edit?usp=sharing for both the AO and MUR search banner pages listed.