no-duplicate-spread-property: handle destructuring assignments

[ajafff]

Only makes sense after renaming in #344

The rule currently ignores the LHS of destructuring assignments. But these could also be checked:

var v: any;
({v, ...{v}} = get<Record<string, any>>());

This just needs an appropriate error message.

OTOH {v, ...{v}} could be simplified to {v, v} by #325

[ajafff]

conclusion: this is not the responsibility of this rule -> implement in no-useless-destructuring in #325