Migrate t_complexity to `QECGatesCost` cost key

[mpharrigan]

With the goal of #539 there are now two built-in ways of counting gates: one where you have to provide which gates to count and another, more-opinionated one that makes some assumptions about the relevant counts for a surface code / lattice surgery / qec execution model. This latter one is QECGatesCost and is similar to the t_complexity protocol. These two protocols should be unified.

• Reduce the amount of dynamacism and magic in existing t_complexity while verifying no regression in t count. This is mostly done, see Unify t-complexity protocol #678 Use build_call_graph instead of decompose_bloq to compute TComplexityfor bloqs #740 Remove sneaky fredkin decomposition #803 Remove _t_complexity_ on MultiAnd and support symbolic cvs #1015 Replace _t_complexity_ with build_call_graph in comparison gates #1012 Remove t_complexity from comparison bloqs #996 Remove _t_complexity_ of CSwapApprox #994
• Split the cirq t-complexity from pure-bloqs t-complexity Introduce types to t_complexity #835
• Remove remaining _t_complexity_ overrides and move logic either to from_directly_countable_bloqs (probably most of them) or duplicate to the my_static_costs generic method otherwise
• make the t_complexity function and method be a wrapper around QECGateCost computation; verify identical resource counts

[mpharrigan]

#1359 makes the default go via QECGateCost

[mpharrigan]

This is done