Generate adjoint blocks for Conjugate expressions

[swernli]

This change introduces a pass to transform away conjugate expressions by generating the appropriate adjoint blocks. It reuses the code introduced for adjoint generation and adds one extra check regarding use of mutable variables inside the apply-block.

With this change, a conjugate expression like this:

within {
    X(q);
    Z(q);
}
apply {
    X(q);
    Z(q);
}

becomes a block expression:

{
    {
        X(q);
        Z(q);
    }
    {
        X(q);
        Z(q);
    }
    {
        Adjoint Z(q);
        Adjoint X(q);
    }
}

[kuzminrobin]

Approving to unblock, but I would recommend at least one more approval.

[DmitryVasilevsky]

I rebased Deutsch-Jozsa branch on top of this (locally) and removed all modifications with manual adjoint/within implementation. I can confirm that it works as expected.

[swernli]

Merging as admin in Cesar's absence as co-owner of the libraries and katas.