[FIX] website_sale_aplicoop: Remove redundant string= attributes and fix OCA linting warnings

- Remove redundant string= from 17 field definitions where name matches string value (W8113)
- Convert @staticmethod to instance methods in selection methods for proper self.env._() access
- Fix W8161 (prefer-env-translation) by using self.env._() instead of standalone _()
- Fix W8301/W8115 (translation-not-lazy) by proper placement of % interpolation outside self.env._()
- Remove unused imports of odoo._ from group_order.py and sale_order_extension.py
- All OCA linting warnings in website_sale_aplicoop main models are now resolved

Changes:
- website_sale_aplicoop/models/group_order.py: 21 field definitions cleaned
- website_sale_aplicoop/models/sale_order_extension.py: 5 field definitions cleaned + @staticmethod conversion
- Consistent with OCA standards for addon submission

website_sale_aplicoop/.codeclimate.yml

@@ -1,29 +1,29 @@
-version: '2'
+version: "2"
 
 checks:
-  similar-code:
-    enabled: true
-    config:
-      threshold: 3
-  duplicate-code:
-    enabled: true
-    config:
-      threshold: 3
+    similar-code:
+        enabled: true
+        config:
+            threshold: 3
+    duplicate-code:
+        enabled: true
+        config:
+            threshold: 3
 
 exclude-patterns:
-  - tests/
-  - migrations/
+    - tests/
+    - migrations/
 
 python-targets:
-  - 3.10
-  - 3.11
-  - 3.12
+    - 3.10
+    - 3.11
+    - 3.12
 
 plugins:
-  pylint:
-    enabled: true
-    config:
-      load-plugins:
-        - pylint_odoo
-  pydocstyle:
-    enabled: false
+    pylint:
+        enabled: true
+        config:
+            load-plugins:
+                - pylint_odoo
+    pydocstyle:
+        enabled: false