Implement writing logic of TSVSerialiser.

Refs #9970.
Move project serialisation logic into saveProjectFolder.

Refs #9970.
Rename saveFolder to saveProjectFile.

Refs #9970.
Refactor saveProjectFolder to be recursive.

Refs #9970.
Remove saveAsTemplate orphans.

These are currently unused and blocking refactoring of saveToString
methods into saveToProject methods. They ought to be relatively easy to
re-add later when needed.

Refs #9970.
Fix bug where <open> was appended to project file.

Refs #9970.
Add saveToProject to IProjectSerialisable and use it.

Refs #9970.
Start refactoring Table to use saveToProject.

Refs #9970.
Refactor Table::saveToProject to use TSVSerialiser.

Refs #9970.
Correct minor error when parsing TableStatistics.

Refs #9970.