Refactor update beacon set mechanism

[hiletmis]

Closes #182

[bbenligiray]

I'd like to keep the signMessage() flow as documentation. Check if the account is 0x07b589f06bD0A5324c4E2376d66d2F4F25921DE1, use signMessage() if it is, use the hardcoded calldata otherwise.

[hiletmis]

@bbenligiray including gas estimation signatures might not be a good idea. Removed it from script and updated the test call data for nodary-rpc-watcher