IDE: codecontext: combine resize and show

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@45307 4005530d-fff6-0310-9dd1-cebe43e6787f
IDE: codecontext: use ClientRect instead of Canvas.ClipRect

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@45308 4005530d-fff6-0310-9dd1-cebe43e6787f