lcl: TCoolBand: reduce updates when creating text label

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@40494 4005530d-fff6-0310-9dd1-cebe43e6787f
lcl: TCoolBand: use alCustom for custom positioned label

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@40495 4005530d-fff6-0310-9dd1-cebe43e6787f