Fix RECS floor area bins

[afontani]

Pull Request Description

Companion: https://github.com/NREL/resstock-estimation/pull/424

There is inconsistency in how the floor area is being calculated across different RECS surveys. This PR corrects this inconsistency.

Resolves additional issues found here: #1273 (comment).

Checklist

Not all may apply:

• Tests (and test files) have been updated
• Documentation has been updated
  • If related to resstock-estimation, checklist includes data dictionary, source report, options saturation, options_lookup.
• Add to the changelog_dev.rst file
• openstudio tasks.rb update_measures has been run
• No unexpected regression test changes on CI (checked comparison artifacts)