[fidl] Remove ordinals from Peridot layer and format.

Done with:
../out/build-zircon/tools/fidl-format -i --remove-ordinals $(grep -l interface $(find . -name \*.fidl | grep -v \.cipd | grep -v third_party ))

(All FIDL files in peridot had explicit ordinals)

This is a "new world" copy of https://fuchsia-review.googlesource.com/c/peridot/+/249052 - proper review can be found there.

Test: CQ
Change-Id: I606e0fd80448719f2d0e0fb62edc173947a1163f