Move contracts publickey in a settings toml file

[giacomo-cc]

Currently we have all the chain smart contracts public keys hardcoded in the codebase:

vyper-cli/src/main.rs

Lines 35 to 38 in c9fc594

	const VYPER_CORE_ID: &str = "vyPErCcGJKQQBeeQ59gXcWrDyU4vBrq8qQfacwmsAsp";
	const REDEEM_LOGIC_FORWARD: &str = "BrpV1re8MshA8qskKVxcEG8zXG3vf2uLX6myeTKAyhsK";
	const RATE_SWITCHBOARD: &str = "2hGXiH1oEQwjCXRx8bNdHTi49ScZp7Mj2bxcjxtULKe1";
	const OTC: &str = "8aHSkExY28qCvg4gnTLU7y1Ev6HnpJ1NxuWb9XtEesVt";

We should move these parameters to an external file for easy tuning. For example it could be a settings.toml file (in order to prepare the field also for future user settings/preferences).

Once created the settings.toml file we can create a new command to open it in a text editor in order to allow users to change it, for example:

vyper-cli settings open

I would avoid creating a command for changing each setting entry from the suite, for now it's not needed.