cmd/puppeth: use geth's prompt to read input

[jwasinger]

fixes #23717

[jwasinger]

Unsure if it's possible now, but I meant to mark this as a draft.

[jwasinger]

Alright, ready for review now.

[holiman]

Without this PR:

[user@work bin]$ ./puppeth 
+-----------------------------------------------------------+
| Welcome to puppeth, your Ethereum private network manager |
|                                                           |
| This tool lets you create a new Ethereum network down to  |
| the genesis block, bootnodes, miners and ethstats servers |
| without the hassle that it would normally entail.         |
|                                                           |
| Puppeth uses SSH to dial in to remote servers, and builds |
| its network components out of Docker containers using the |
| docker-compose toolset.                                   |
+-----------------------------------------------------------+

Please specify a network name to administer (no spaces, hyphens or capital letters please)
> foobar^[[D^[[C^[[D^C

I typed foobar then tried to go left/right, and then ctrl-c to exit.

With this PR:

[user@work bin]$ ../../cmd/puppeth/puppeth 
+-----------------------------------------------------------+
| Welcome to puppeth, your Ethereum private network manager |
|                                                           |
| This tool lets you create a new Ethereum network down to  |
| the genesis block, bootnodes, miners and ethstats servers |
| without the hassle that it would normally entail.         |
|                                                           |
| Puppeth uses SSH to dial in to remote servers, and builds |
| its network components out of Docker containers using the |
| docker-compose toolset.                                   |
+-----------------------------------------------------------+

Please specify a network name to administer (no spaces, hyphens or capital letters please)
> foo^C
CRIT [10-13|09:37:08.545] Failed to read user input                err="prompt aborted"

The left-right worked well, but then ctrl-c caused a CRIT error, which might not be what we want (?)

[jwasinger]

Ooh yes. Good catch.

[jwasinger]

Alright. Should be good to go now.

[holiman]

LGTM