fdo#74584: Revert various previous changes to upcase HTML tags.

This reverts

    commit 3c84fa61570113d1dfb2523ab88f268eeeb46c3c.
    commit 96a1f60aeb2a7954533da9b4aa4947efb7a65e70.
    commit 1f74a3ce201bad68f160584900285e2c087ab2c0.
    commit 3d481254a07fe82d11953f9825a2f8fc6eeabc0b.
fdo#74584: These tags should be lowercase for correct clipboard handling.

Change-Id: I323b96cecbf7158919fad534a202f158965ca99f