Consider renaming EFNYC related components and variables in the Tenant Platform to "evictionfree"

[sraby]

Now that we have transitions our EFNYC tool to Eviction Free NY, and have a new site within the tenants2 repo, let's consider updating the naming of EFNYC related code (specifically that which gets referenced in DDO and in #1916) and perhaps changing the EFNYC_ORIGIN Global App Server variable

[toolness]

@samaratrilling this might be a good first issue, since it basically involves renaming things from EFNYC to EVICTIONFREE, I think...

[samaratrilling]

Mostly a find and replace situation here. Tests/linter/type checker will complain if these are out of whack or improperly done.