This commit ports the numeric portion of the Isometry gate class to
rust. While this will likely improve the performance slightly this move
is more to make isolate this code from blas/lapack in numpy. We're
hitting some stability issues on arm64 mac in CI and moving this code to
rust should hopefully fix this issue. As this is more for functional
reasons no real performance tuning was done on this port, there are
likely several opportunities to improve the runtime performance of the
code.

The UCGate class is used almost exclusively by the Isometry class to
build up the definition of the isometry circuit. There were also some
linear algebra inside the function which could also be the source of the
stability issues we were seeing on arm64. This commit ports this
function as part of the larger isometry migration.

This commit removes the use of bit string manipulations that were
faithfully ported from the original python logic (but left a bad taste
in my mouth) into more efficient bitwise operations (which were
possible in the original python too).

The use of intermediate Vec<u8> as proxy bitstrings was originally
ported nearly exactly from the python implementation. But since
everything is working now this commit switches to use bitwise operations
where it makes sense as this will be more efficient.

Co-authored-by: Jake Lishman <jake@binhbar.com>

Co-authored-by: John Lapeyre <jlapeyre@users.noreply.github.com>