[mlir][Linalg] NFC - Cleanup Linalg Declarative Transformations

Summary:
This is part of an ongoing cleanup and uniformization work.

This diff performs 3 types of cleanups:
1. Uniformize transformation names.
2. Replace all pattern operands that need not be captured by `$_`
3. Replace all usage of pattern captured op by the normalized `op` name (instead of positional parameters such as `$0`)

Reviewers: ftynse

Subscribers: mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72081