validation fix (dir structure), v2 fs is post, update validation graphs to do v1/v2 tests

[juztas]

• Directory restructure broke validation: doe-iri/iri-facility-api-docs@6465796 (had a quick chat with John; we need to agree on the structure for the docs repo). The docs repo acts as the " source of truth" for validation; @jmacauley
• Update v2 spec (after 1 is done) to use POST; @juztas
• Update schemathesis validation to use the new structure (1, 2), and also update validation runtime (GitHub action) to include tests for v1/v2 @juztas

After these, #101 - should succeed.