De-parametrize types in node crate

[ales-otf]

Is your feature request related to a problem? Please describe.

In node-subtensor crate, we have a lot of generics, which are actually rudiments of the node template. While they are useful for templating, they complicate code in case of a concrete implementation.

Describe the solution you'd like

Remove unnecessary generics and replace them with concrete types.

Describe alternatives you've considered

No response

Additional context

No response