Arm backend: Add dim mapping helpers (#20222)

Dim args such as sum(dim=1) needs to be transformed when swapping place
with operators which change
shape, i.e. permutes and views.

ViewMap and PermuteMap handles and validates these transforms for
reduction dims and permute dims.


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Signed-off-by: Adrian Lundell <adrian.lundell@arm.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: AdrianLundell