Automerge: [NFC][Linalg] Introduce ConvMatchBuilder + refactor Conv matchers (#169704)

-- This commit is a follow-up and third in the series of adding
matchers for conv/pool ops. Refer:
llvm/llvm-project#163724
-- It introduces ConvMatchBuilder class in order to reduce the
   repetitive code across Conv1D/2D/3D/Depthwise/Pooling variants.
-- Refer to [Conv2D
thread](llvm/llvm-project#168362 (comment))
for further context.

Signed-off-by: Abhishek Varma <[email protected]>

Author: Abhishek-Varma