This commit is a follow-up to Qiskit#9578 which added a rust implementation
of the second half of the single qubit euler decomposition routines and
leveraged them for the Optimize1qGatesDecomposition transpiler pass.
With that PR the Optimize1qGatesDecomposition no longer was dependent on
the OneQubitEulerDecomposer class. This commit continues from that PR
and updates the OneQubitEulerDecomposer to leverage the same Rust
implementation internally. Calling a decomposer object will internally
call the rust function to generate a circuit sequence and then return
either a QuantumCircuit or DAGCircuit (depending on the options).
Similarly all the angle computation is done directly in Rust.

The python version of the OneQubitEulerDecomposer class had atol
clamping on it's output from mod_2pi, when this function was ported to
rust this was not included. At the time it was because nothing set the
atol parameter when calling mod_2pi (the angle calculation in Qiskit#9185 did
not have atol and the expansion to construct circuits for
Optimize1qGatesDecomposition always used the default value). However,
now that we're expanding OneQubitEulerDecomposer to internally do all
the calculations in rust we need to support an adjustable atol which
includes the missing endpoint clamping in mod_2pi. This commit adds this
missing functionality to the function.