Patch qmake hard-coded QT_PREFIX_PATH

Changed

• Patch qmake when finishing installation.(#100)
  qmake has a hard-coded prefix path, and aqt modify binary in finish phase.
  it is not necessary for Qt 5.14.2, 5.15.0 and later.
  This behavior try to be as same as a Qt installer framework doing.
• Patch Framework.QtCore when finishing installation.(#100)
  As same as qmake, framework also has a hard-coded prefix path.
  (Suggestions from @agateau)