Project Inspector: A new button for adding files from file system easily. Issue #24337.

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@46311 4005530d-fff6-0310-9dd1-cebe43e6787f
Package Editor: A new button for adding files from file system easily. Issue #24337.

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@46312 4005530d-fff6-0310-9dd1-cebe43e6787f