Remove reliance on django-markdownx (#3231)

* Remove reliance on django-markdownx

- We are now rendering notes on the client side using easymde
- No longer any need to utilize the markdownx integration
- Adds character limit for notes fields`

* Adjust legacy migrations - remove references to markdownx

* Fix bug for company notes field

InvenTree/stock/migrations/0018_auto_20200202_0103.py

@@ -1,7 +1,6 @@
 # Generated by Django 2.2.9 on 2020-02-02 01:03
 
-from django.db import migrations
-import markdownx.models
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
@@ -14,6 +13,6 @@ class Migration(migrations.Migration):
         migrations.AlterField(
             model_name='stockitem',
             name='notes',
-            field=markdownx.models.MarkdownxField(blank=True, help_text='Stock Item Notes'),
+            field=models.TextField(blank=True, help_text='Stock Item Notes'),
         ),
     ]

InvenTree/stock/migrations/0020_auto_20200206_1213.py

@@ -1,7 +1,6 @@
 # Generated by Django 2.2.9 on 2020-02-06 12:13
 
-from django.db import migrations
-import markdownx.models
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
@@ -14,6 +13,6 @@ class Migration(migrations.Migration):
         migrations.AlterField(
             model_name='stockitem',
             name='notes',
-            field=markdownx.models.MarkdownxField(blank=True, help_text='Stock Item Notes', null=True),
+            field=models.TextField(blank=True, help_text='Stock Item Notes', null=True),
         ),
     ]

InvenTree/stock/migrations/0034_auto_20200426_0602.py

@@ -4,7 +4,6 @@ import InvenTree.fields
 import django.core.validators
 from django.db import migrations, models
 import django.db.models.deletion
-import markdownx.models
 import mptt.fields
 
 
@@ -56,7 +55,7 @@ class Migration(migrations.Migration):
         migrations.AlterField(
             model_name='stockitem',
             name='notes',
-            field=markdownx.models.MarkdownxField(blank=True, help_text='Stock Item Notes', null=True, verbose_name='Notes'),
+            field=models.TextField(blank=True, help_text='Stock Item Notes', null=True, verbose_name='Notes'),
         ),
         migrations.AlterField(
             model_name='stockitem',

InvenTree/stock/migrations/0077_alter_stockitem_notes.py

@@ -0,0 +1,19 @@
+# Generated by Django 3.2.13 on 2022-06-20 07:28
+
+import InvenTree.fields
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('stock', '0076_alter_stockitem_status'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='stockitem',
+            name='notes',
+            field=InvenTree.fields.InvenTreeNotesField(blank=True, help_text='Stock Item Notes', max_length=50000, null=True, verbose_name='Notes'),
+        ),
+    ]