Bytes should be a DTypePointer instead of a List

[saviorand]

Issue raised by the author of https://github.com/alainrollejr/mocodes

Is your feature request related to a problem? Please describe.
The application does operations on Int8 bytes, so performance is important

Describe the solution you'd like
Bytes() should be an Int8 DTypePointer instead of a List. This should allow to make operations with less computational overhead (in theory)

Describe alternatives you've considered
Potentially can reference the Bytes() implementation in Basalt, a Mojo ML framework: https://github.com/basalt-org/basalt