Implement semantic of the While statement

[meevee98]

Closes #8
This pull request depends on #13 because of the unit tests. While it isn't merged, I'm setting this as a draft.

[Thacryba]

Hello! Sorry by the lack of time...
I was making some tests with this PR and this is what I got: 👍

Tests

1. The result of the operation Equality between integers inside the while condition.
   Expected: It should be no semantic error.
   Result: The code was translated without semantic errors.

2. The result of the operation Inequality between integers inside the while condition.
   Expected: It should be no semantic error.
   Result: The code was translated without semantic errors.

3. The result of the operation Greater Then between integers inside the while condition.
   Expected: It should be no semantic error.
   Result: The code was translated without semantic errors.

4. The result of the operation Greater Then or Equal between integers inside the while condition.
   Expected: It should be no semantic error.
   Result: The code was translated without semantic errors.

5. The result of the operation Less Then between integers inside the while condition.
   Expected: It should be no semantic error.
   Result: The code was translated without semantic errors.

6. The result of the operation Less Then or Equal between integers inside the while condition.
   Expected: It should be no semantic error.
   Result: The code was translated without semantic errors.

7. The result of the operation Equality between integer and character inside the while condition.
   Expected: Error Type.
   Result: line 7:19 Operator '=' cannot be applied to 'Integer', 'Character'

8. The result of the operation sum between integers inside the while condition.
   Expected: Error Type.
   Result: line 7:25 no viable alternative at input 'var1+var2)' null

9. The result of the operation subraction between integers inside the while condition.
   Expected: Error Type.
   Result: line 7:25 no viable alternative at input 'var1-var2)' null

10. The result of the operation division between integers inside the while condition.
    Expected: Error Type.
    Result: line 7:27 no viable alternative at input 'var1divvar2)' null

11. The result of the operation multiplication between integers inside the while condition.
    Expected: Error Type.
    Result: line 7:25 no viable alternative at input 'var1*var2)' null

12. The result of the operation modulo between integers inside the while condition.
    Expected: Error Type.
    Result: null line 7:27 no viable alternative at input 'var1modvar2)'

13. The result of the operation AND between booleans with value true inside the while condition.
    Expected: It should be no semantic error.
    Result: The code was translated without semantic errors.

14. The result of the operation OR between booleans with value true inside the while condition.
    Expected: It should be no semantic error.
    Result: The code was translated without semantic errors.

15. The result of the operation XOR between booleans with value true inside the while condition.
    Expected: It should be no semantic error.
    Result: The code was translated without semantic errors.

16. The result of the operation NOT with a boolean with value true inside the while condition.
    Expected: It should be no semantic error.
    Result: The code was translated without semantic errors.

Some variations of this code were used in the test:

procedimento principal
inicio
    var1: inteiro;
    var1 <- 1;
    var2: inteiro;
    var2 <- 3;
    enquanto (var1 < var2) faca 
        var1 <- var1 + var2;
    fim
fim