pytket v1.18.0 release candidate 0

Update `auto_rebase_pass` to take optional `allow_swaps` argument (#947)

* Further changes to auto rebase

* Undo accidental commited changes

* Remove comments, working up to phase

* Update CircPool.cpp

* Update Rebase.cpp

* Remove comments from transform_test and add gate count assertions

* Remove redundant commented out code

* bump

* add c++ tests

* update auto rebase and add tests for CX case

* Update CircPool.cpp

* clang format update

* update changes for sycamore gate

* Add tests for new zzphase and tk2 sswap cases

* Update auto_rebase.py

* Update changelog.rst

* Update test_CompilerPass.cpp

* Update test_CompilerPass.cpp

* Update test_CompilerPass.cpp

* Update CircPool.cpp

* Remove sycamore tests

* Update CircPool.cpp

* Update CircPool.cpp

* Move TK2 SWAP decomp into c++, update overall method

* Rewrite swap replacement ot be basic

* Update test_CompilerPass.cpp

* Fix missing space and readd python tests

* Update transform_test.py

* Update transform_test.py