[Types] Represent boolean type as uint1

[chhzh123]

Description

This PR fixes the incorrect representation of the boolean type in Allo. Boolean type should be represented as uint1 instead of int1. Notice 1 in int1 is actually -1 since the highest bit is represented as the sign bit.

Examples

def test_boolean():
    def kernel(A: bool[16]) -> bool[16]:
        B: bool[16] = 0
        for i in range(16):
            if A[i]:
                B[i] = 1
            else:
                B[i] = 0
        return B

    s = allo.customize(kernel)
    print(s.module)
    mod = s.build()
    np_A = np.random.randint(0, 2, size=(16)).astype(np.bool)
    np_B = mod(np_A)
    np.testing.assert_array_equal(np_A, np_B)

Checklist

• PR's title starts with a category (e.g. [Bugfix], [IR], [Builder], etc)
• Changes are complete (i.e. I finished coding on this PR)
• All changes have test coverage (It would be better to provide ~2 different test cases to test the robustness of your code)
• Code is well-documented