Tidy up inst directory, (re)move config files for tests

[CarlijnB]

Tidy up inst directory by either moving or removing config files that are used only for package testing.

• Move these into the test directory
• To limit number of files, I/O, etc. it might be possible to delete some config files & replace them by setting of options via the change_config functions

[CarlijnB]

Have moved these into test directory