[mlir] Rename BufferAliasAnalysis to BufferViewFlowAnalysis

This it to make more clear the difference between this and
an AliasAnalysis.

For example, given a sequence of subviews that create values
A -> B -> C -> d:
BufferViewFlowAnalysis::resolve(B) => {B, C, D}
AliasAnalysis::resolve(B) => {A, B, C, D}

Differential Revision: https://reviews.llvm.org/D100838