Sendinblue: rename to Brevo

* Update docs to (usually) refer to Brevo rather than Sendinblue
* Change SENDINBLUE_API_URL to api.brevo.com
   (same API is available on both domains)
* Leave code references (settings, backend name, webhook urls)
   unchanged as `sendinblue`, to avoid unnecessary client changes

tests/test_sendinblue_backend.py

@@ -67,7 +67,7 @@ class SendinBlueBackendStandardEmailTests(SendinBlueBackendMockAPITestCase):
             ["to@example.com"],
             fail_silently=False,
         )
-        self.assert_esp_called("https://api.sendinblue.com/v3/smtp/email")
+        self.assert_esp_called("https://api.brevo.com/v3/smtp/email")
         http_headers = self.get_api_call_headers()
         self.assertEqual(http_headers["api-key"], "test_api_key")
         self.assertEqual(http_headers["Content-Type"], "application/json")

tests/test_sendinblue_integration.py

@@ -112,7 +112,7 @@ class SendinBlueBackendIntegrationTests(AnymailTestMixin, SimpleTestCase):
             metadata={"customer-id": "ZXK9123", "meta2": 2},
         )
 
-        # Normal attachments don't work with Sendinblue templates:
+        # Normal attachments don't work with Brevo templates:
         #   message.attach("attachment1.txt", "Here is some\ntext", "text/plain")
         # If you can host the attachment content on some publicly-accessible URL,
         # this *non-portable* alternative allows sending attachments with templates:
@@ -120,7 +120,7 @@ class SendinBlueBackendIntegrationTests(AnymailTestMixin, SimpleTestCase):
             "attachment": [
                 {
                     "name": "attachment1.txt",
-                    # URL where Sendinblue can download the attachment content while
+                    # URL where Brevo can download the attachment content while
                     # sending (must be content-type: text/plain):
                     "url": "https://raw.githubusercontent.com/anymail/django-anymail/"
                     "main/docs/_readme/template.txt",