This commit adds a default value to the generate_preset_pass_manager's
optimization_level argument. If it's not specified optimization level 2
will be used. After Qiskit#12148 optimization level 2 is a better fit for an
optimal tradeoff between heuristic effort and runtime that makes it
well suited as a default optimization level.

…et-pass-manager

This commit updates the transpile() function's optimization_level argument
default value to match generate_preset_pass_manager's new default to use 2
instead of 1. This is arguably a breaking API change, but since the
semantics are equivalent with two minor edge cases with implicit behavior
that were a side effect of the level 1 preset pass manager's construction
(which are documented in the release notes) we're ok making it in this
case. Some tests which we're relying on the implicit behavior of
optimization level 1 are updated to explicitly set the optimization
level argument which will retain this behavior.

…generate-preset-pass-manager

* Replace use of transpile with specific pass in  HLS tests.

…generate-preset-pass-manager

…generate-preset-pass-manager

…generate-preset-pass-manager

….com/mtreinish/qiskit-core into default-generate-preset-pass-manager