So far all SME2 implementations only used the SME feature set, so it
makes sense to rename it to just SME and compile it for the SME
extension. That way future implementations using SME2 features can be
distinguished.

Changes related to filenames are part of a separate commit.

Gaussian Blur 15x15 kernels always use the custom sigma variant,
with much better performance and near the same accuracy.
Custom Sigma kernels are uniformized and simplified using
std::reference_wrapper in the SVE variant.

Update documentation with oldest supported GCC version as well.

Yufeng Shi authored Jan 29, 2025 and Denes Tarjan committed Feb 06, 2025

 1. Refactor RemapF32 and Warp_Perspective SVE2 Implementation
 2. Enable constant border for RemapF32 Neon Implementation
 3. Refactor test_remap.cpp and add tests for constant border

The purpose of this change is to avoid the cost of supporting many
versions of OpenCV.

Repurposes existing u8 implementations of remap_s16 for Neon and SVE2,
and makes them work for source type u16.

Michael Platings authored Dec 12, 2024 and Denes Tarjan committed Dec 18, 2024

Also update signature of remap and warp_perspective functions to avoid
the same mistake there.