This renames:
- `arm_sme.move_tile_slice_to_vector` to `arm_sme.extract_tile_slice`
- `arm_sme.move_vector_to_tile_slice` to `arm_sme.insert_tile_slice`
The new names are more consistent with the rest of MLIR and should be
easier to understand. The current names (to me personally) are hard to
parse and easy to mix up when skimming through code.
Additionally, the syntax for `insert_tile_slice` has changed from:
```mlir
%4 = arm_sme.insert_tile_slice %0, %1, %2
: vector<[16]xi8> into vector<[16]x[16]xi8>
```
To:
```mlir
%4 = arm_sme.insert_tile_slice %0, %1[%2]
: vector<[16]xi8> into vector<[16]x[16]xi8>
```
This is for consistency with `extract_tile_slice`, but also helps with
readability as it makes it clear which operand is the index.
Existing 'arith::ConstantOp' conversion and tests are moved from
VectorToArmSME. There's currently only a single op that's converted at
the moment, but this will grow in the future as things like in-tile add
are implemented. Also, 'createLoopOverTileSlices' is moved to ArmSME
utils since it's relevant for both conversions.
