Added changes from osmandapp/OsmAnd#10542 and osmandapp/OsmAnd#10587

[jensMF]

Why:

• PRs fix #1326 and #10209 by adding the XML namespace 'osmand' to the header and the writeExtensions function OsmAnd#10542 and Add BaseCamp compatibility for planned Tracks and claculated routes exported to gpx OsmAnd#10587 made changes in the gpx files
• as stated there, a name space with the name 'osmand' was created and added to all extensions
• the order of wpt, rte and trk was changed to comply with the gpx 1.1 standard and to have BaseCamp/Garmin compatibility

What's being changed:

the osmand name space was added to extensions and the order of rte and trk was changed

Check off the following:

• All of the tests are passing.
• I have reviewed my changes in staging. (look for the deploy-to-heroku link in your pull request, then click View deployment)
• For content changes, I have reviewed the localization checklist
• For content changes, I have reviewed the Content style guide for GitHub Docs.