Backup and restore facilities

Added backup and restore facilities for grid and dofvector. Either call

problemStat.backup(adaptInfo);

(This will backup the files to [name]->backup->grid and [name]->backup->solution) and instead of initialize() call the function

problemStat.restore(INIT_ALL);

(This will read the grid and solution from the files [name]->restore->grid and [name]->restore->solution)

Or you can call

problemStat.backup(filename)

and

problemStat.restore(filename) -> std::unique_ptr<Grid>

directly to backup and restore the grid of the problemStat and dofvector.backup(filename) and dofvector.restore(filename) to backup and restore the data of the dofvector.

If the grid does not support backup-restore, the current gridView is written. This means that the hierarchy information is lost. A warning is printed in this case.

changed title from Feature/backup restore to Backup and restore facilities

changed the description

added 1 commit

• fb26f4c1 - added missing template parameter in Writer

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added 1 commit

• e2aefebc - replace try-catch with grid capability check

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resolved all discussions

mentioned in commit d0a4cbdf

merged