Add 3.3V and 5V output control

[21km43]

I added these commands, and already tested on WCH-LinkE.

> wlink set-power --help 
Enable or disable power output

Usage: wlink set-power [OPTIONS] <COMMAND>

Commands:
  enable3v3   Enable 3.3V output
  disable3v3  Disable 3.3V output
  enable5v    Enable 5V output
  disable5v   Disable 5V output
  help        Print this message or the help of the given subcommand(s)

example

> wlink set-power enable3v3
13:31:46 [INFO] Connected to WCH-Link v2.12(v32) (WCH-LinkE-CH32V305)
13:31:46 [INFO] Enable 3.3V Output

> wlink set-power disable3v3
13:31:52 [INFO] Connected to WCH-Link v2.12(v32) (WCH-LinkE-CH32V305)
13:31:52 [INFO] Disable 3.3V Output

> wlink set-power enable5v
13:32:03 [INFO] Connected to WCH-Link v2.12(v32) (WCH-LinkE-CH32V305)
13:32:03 [INFO] Enable 5V Output

> wlink set-power disable5v
13:32:07 [INFO] Connected to WCH-Link v2.12(v32) (WCH-LinkE-CH32V305)
13:32:07 [INFO] Disable 5V Output

When merge this PR, I recommend that squash and merge.

[21km43]

Debug done.
If someone have a idea of command fotmat, feel free to comment to this PR

[andelf]

Better make them grouped into a SetPower(commands::SetPower) sub-command.

[21km43]

Thank you for review.
I grouped them into sub-command.
Detail: 35b3713

[andelf]

Looks great! Approved.