fix: allow constant/trait constants depend on each other

[i582]

Issue

Closes #924
Closes #1645

Checklist

• I have updated CHANGELOG.md
• I have added tests to demonstrate the contribution is correctly implemented: this usually includes both positive and negative tests, showing the happy path(s) and featuring intentionally broken cases
• I have run all the tests locally and no test failure was reported
• I have run the linter, formatter and spellchecker
• I did not do unrelated and/or undiscussed refactorings

[anton-trunov]

@jeshecdom please review the interpreter changes

[jeshecdom]

What error message will you get if you do something like this?

contract Test {

    a: Int = 1;
    const B: Int = 10;
    const A: Int = self.B + self.test();
    
    fun test(): Int {
        return self.a;
    }
}

[jeshecdom]

I think this PR should be put on hold after issue #1655 is resolved first, because it is related to constant initialization.