Tests passing now; still needs manual testing before this is ready to merge.

modules/salesforce_mapping/salesforce_mapping.install

modules/salesforce_mapping/src/Entity/MappedObject.php

modules/salesforce_mapping/src/Form/MappedObjectForm.php

modules/salesforce_mapping/src/MappedObjectStorageSchema.php

...force_mapping/src/Tests/SalesforceMappingCrudFormTest.php

...alesforce_mapping/tests/src/Unit/MappedObjectListTest.php

...es/salesforce_mapping/tests/src/Unit/MappedObjectTest.php

modules/salesforce_pull/src/Plugin/QueueWorker/PullBase.php

modules/salesforce_pull/tests/src/Unit/DeleteHandlerTest.php

modules/salesforce_push/salesforce_push.module

...rce_push/src/Plugin/SalesforcePushQueueProcessor/Rest.php