consolidate export config of local storage test steps

[individual-it]

the steps
Given the administrator has created a json file with exported config of local storage mount "TestMountPoint" to "mountConfig.json" in temporary storage in \WebDav::theAdminHasCreatedAJsonFileWithExportedMountConfig
and the combination of

Given the administrator has exported the local storage mounts using the occ command
 And the administrator has created a file "exportedMounts.json" in temporary storage with the last exported content using the testing API

in \OccContext::theAdministratorHasExportedTheMountsUsingTheOccCommand & \FeatureContext::theAdministratorHasCreatedAFileInTemporaryStorageWithLastExportedContent

look very similar to me except of the mount point option.
Maybe we can DRY the code and also don't have the scattered over 3 files.