[REM] website_sale_aplicoop: remove dead code and orphaned tests

Duplicate _translate_labels fallback, unreachable /eskaera/add-to-cart and
/eskaera/save-cart routes (the frontend cart is localStorage-only and uses
save-order), redundant pickup wrappers, unused pagination/count helpers and
fields, deprecated JS shims, and the already-empty checkout_summary.js and
i18n key/init leftovers.

Also drops 11 tests/*.py never wired into tests/__init__.py: three were
unimplemented placeholders (setUp with no assertions), and the other eight
had real assertions but were bit-rotted against the current schema (e.g.
res.partner.is_supplier no longer exists) — wiring them in surfaced 43
failures unrelated to this cleanup. Verified 0 failed/0 errors of 270 tests
both before and after.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

website_sale_aplicoop/controllers/website_sale_i18n.py

@@ -149,18 +149,3 @@ def _get_translated_labels(self, lang=None, request_obj=None):
     }
 
     return labels
-
-
-def _translate_labels(self, labels_dict, lang):
-    # Minimal fallback translator kept here; prefers env translations
-    translations = {
-        "es_ES": {},
-    }
-    lang_translations = translations.get(lang, {})
-    translated = {}
-    for key, english_label in labels_dict.items():
-        translated[key] = lang_translations.get(english_label, english_label)
-    _logger.info(
-        "[_translate_labels] Language: %s, Translated %d labels", lang, len(translated)
-    )
-    return translated