LCL, TCustomControlFilterEdit: minor optimization.

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@45838 4005530d-fff6-0310-9dd1-cebe43e6787f
Packager: Fill tree view through FilterEdit in UpdateNewInstalledPackages in Install/uninstall packages dlg. Fix tab order of controls.

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@45839 4005530d-fff6-0310-9dd1-cebe43e6787f
Packager: Add OnShow handler in Install/uninstall packages dlg to update (filter)-text. Issue #26433

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@45840 4005530d-fff6-0310-9dd1-cebe43e6787f