Clean up AIE attrs

[makslevental]

This PR normalizes/cleans up some things about AIE Attrs.

1. DMABDOp::AB becomes an actual enum DMABDBuffer instead of a ConfinedAttr[0,1]
2. DimTuple becomes the more semantically legible BDDimLayout with struct parsing <wrap = 2, step = 128> instead of tuple parsing. DimTupleArray and DimTupleArrayArray are renamed correspondingly.

Note, in order to make the assembly ~reasonable, stepsize becomes step.

[github-actions]

Coverage Report

Created: 2023-12-21 17:55

Click here for information about interpreting this report.

Filename	Function Coverage	Line Coverage	Region Coverage	Branch Coverage
include/aie/Dialect/AIE/IR/AIEDialect.h	80.77%	59.82%	62.16%	6.25%
lib/Dialect/AIE/IR/AIEDialect.cpp	92.11%	83.36%	85.99%	76.03%
lib/Dialect/AIE/Transforms/AIEObjectFifoStatefulTransform.cpp	100.00%	95.65%	94.62%	89.73%
lib/Dialect/AIEX/Transforms/AIELowerMemcpy.cpp	100.00%	97.26%	90.00%	75.00%
Totals	92.47%	88.74%	88.68%	80.71%

Generated by llvm-cov -- llvm version 14.0.0