Fix typos/naming (#4242)

* fix usage of InvenTree name

* small typo fix

* rename notification plugin
all builtins should be named inventree...

.github/actions/migration/action.yaml

@@ -1,6 +1,6 @@
 name: 'Migration test'
 description: 'Run migration test sequenze'
-author: 'inventree'
+author: 'InvenTree'
 
 runs:
     using: 'composite'

.github/actions/setup/action.yaml

@@ -1,6 +1,6 @@
 name: 'Setup Enviroment'
 description: 'Setup the enviroment for general InvenTree tests'
-author: 'inventree'
+author: 'InvenTree'
 inputs:
     python:
         required: false