fix: add validation to whitelist input

[wa0x6e]

Summary

Closes: #121

• Add validation to whitelist input
• Accept , as delimiter, in addition of exisiting newline

How to test

1. Go to http://localhost:8080/#/create
2. Move to Voting power steps
3. Add a "Whitelist" strategy
4. Try inputting some invalid and valid values in the "whitelist" input
5. It should show an error when the input is not valid
6. Create the space
7. It should create the space without errors

Notes

• The input should accept only format ADDRESS:VP
• Multiple values can be delimited by a new line and/or by ,
• Empty lines should be ignored
• Blank spaces should be ignored (ADDRESS:VP, ADDRESS : VP are both valid

[Sekhmet]

@wa0x6e looks good to me, tests are broken because we are comparing arrays to strings now.