Added capability to merge organisations

- Added an interface for organisation
- Added beforeDelete and beforeMerge callbacks
- Added hard/soft delete to organisations

schema/requests/organisation/merge.yaml

@@ -0,0 +1,25 @@
+---
+source_slug:
+  validators:
+    required:
+      label: "&SOURCE_SLUG"
+      message: VALIDATE.REQUIRED
+    length:
+      label: "&SOURCE_SLUG"
+      min: 1
+      max: 255
+      message: VALIDATE.LENGTH_RANGE
+  transformations:
+  - trim
+target_slug:
+  validators:
+    required:
+      label: "&TARGET_SLUG"
+      message: VALIDATE.REQUIRED
+    length:
+      label: "&TARGET_SLUG"
+      min: 1
+      max: 255
+      message: VALIDATE.LENGTH_RANGE
+  transformations:
+  - trim