C#: Bitmap Commands

### Description

Bitmap commands support for C# 

Full list is listed in https://github.com/valkey-io/valkey-glide/wiki/ValKey-Commands-Implementation-Progress

## Commands

- [ ] `bitfield` -
- [ ] `setbit`
- [ ] `getbit`
- [ ] `bitcount`
- [ ] `bitop`
- [ ] `bitfield_ro`
- [ ] `bitpos`