Feat(auth): Remove auth provider entity (#6314)

**What**
- remove auth provider entity

**Why**
- The auth provider entity was not really used anywhere

**How**
- Keeping loader behavior as is but removing the 

Co-authored-by: Sebastian Rindom <7554214+srindom@users.noreply.github.com>

.changeset/smooth-penguins-vanish.md

@@ -0,0 +1,5 @@
+---
+"@medusajs/utils": patch
+---
+
+feat(utils): return array or single entity based on input for modules created by internal module service factory