Searchers can click to see more jobs w/o getting a 404

[MothOnMars]

USAJobs updated their search engine and the query syntax changed. In the link below, we send users here (see screendshot):

https://www.usajobs.gov/JobSearch/Search/GetResults?organizationid=GS&PostingChannelID=USASearch&ApplicantEligibility=all

The new syntax for the above should be:

https://www.usajobs.gov/Search/?a=gs&hp=public

For agencies with multiple organization codes, the syntax has changed from:
organizationid=GS;HI
To:
a=GS&a=HI

So we need to update the endpoint we're sending people to, and change the parameters that get built in this URL within our jobs module on the serps.
organizationid -> a
ApplicantEligibility -> hp

Acceptance criteria:
[ ] clicking on the link to see more job postings on USAJobs should take me to a list of the relevant agency's job postings that are open to the public on USAJobs.

References:
https://search.gov/manual/govbox-jobs.html

[MothOnMars]

Resolved by 4469770