fix: token flag for cluster pay

[dtdang]

What I did

Looks for the token symbol if the address is valid or if the token symbol is given then it compares it to the accepted tokens list for the network.

fixes: #170

How I did it

How to verify it

Checklist

• Passes all linting checks (pre-commit and CI jobs)
• New test cases have been added and are passing
• Documentation has been updated
• PR title follows Conventional Commit standard (will be automatically included in the changelog)

[fubuloubu]

I think you could do something like check if it's an address, and then do this without a try...except

[dtdang]

I've tried checking for an address without a try...except but even using convert will need one. The first method will check if it an address by association if the Contract(token) gives a value error but the new push checks using convert and will give a ConversionError. Both do the same thing but the second is more descriptive.