Arm64: Rename AdvSimd/Sve Load/Store vector API names

[kunalspathak]

AdvSimd

1. Rename LoadVector128xN to LoadNxVector128
   • Consistent naming. See [API Proposal]: Arm64: FEAT_SVE: loads pt 2 #97831 (comment)
2. Rename StoreVectorNxMAndZip to StoreVectorAndZip
   • The type on which the API is operation on can be known from parameters. As such we do not need special naming for them.
3. Rename StoreVectorNx2 to Store
   • Same reason as point 2) above.

Sve

1. Rename LoadNxVector to LoadNxAndUnzip

   • The operation does the unzip, similar to how it is done in AdvSimd. Compare left side operation vs. "4th quadrant" of right side.
     

2. Rename Store to StoreAndZip

   • Same reason as point 1) above

Discussion: #102180 (comment)

[kunalspathak]

cc: @tannergooding @dotnet/arm64-contrib

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