Validator Index Verify

[AgeManning]

The ergonomics of this can be improved I think.

I have a mnemonic and I don't know what index to use. I was hoping Siren could help. Currently the following happens:

1. I input mnemonic
2. Siren asks me for an index (I dont know, so I put 0)
3. Siren tells me 3 are in use
4. Ok, so I put in index 3
5. Siren tells me the next 3 are in use
6. Ok, so I put in index 5, siren tells me only one is in use and then the next two are available.

I think it would be better to avoid all these steps to do the following:
When asking for an index, already lookup which are in use starting from index 0 (without user input). If 0 is in use, check 1, if 1 is in use check 2 and so on, until we find the index that is not in use (up to 100 or so). Then display to the user the first 3 that are in use and also list the next available index.

So once the user inputs their mnemonic, siren will show them, the first 3 in-use validators and the next available index. With that information the user can then set their index. We could even default the textbox with the next available index.

The reason I think showing the first few validators is useful, is because I have a few mnemonics and its useful to know which mnemonic I'm using

[AgeManning]

Oh i tried again with another mnemonic. It seems it looks ahead just for the number of validators you want to add.

I'm using firefox. I didn't realise I could scroll down the list, because there were no scroll bars or indication that I could move down the list, it just showed 3 in use.

As an added bonus (if it's not too hard to do), I noticed that i showed "In use" for validators that had been existed. It might be nice to differentiate as it would help me remember what has been done with the vals. I.e "In Use" or "Existed". Not sure if we want other states in there.