init: Euro-Office Odoo 16.0 modules

Based on onlyoffice_odoo by Ascensio System SIA (ONLYOFFICE, LGPL-3).
Rebranded and adapted for Euro-Office by bring.out d.o.o.

Modules:
- eurooffice_odoo: base integration
- eurooffice_odoo_templates: document templates
- eurooffice_odoo_oca_dms: OCA DMS integration (replaces Enterprise documents)

All references renamed: onlyoffice -> eurooffice, ONLYOFFICE -> Euro-Office.
Original copyright notices preserved.

odoo-bringout-eurooffice-eurooffice_odoo_templates/eurooffice_odoo_templates/utils/pdf_utils.py

@@ -0,0 +1,39 @@
+# TODO: add convert docx to pdf
+
+
+def is_pdf_form(text):
+    if not text:
+        return False
+
+    index_first = text.find(b"%\xcd\xca\xd2\xa9\x0d")
+    if index_first == -1:
+        return False
+
+    p_first = text[index_first + 6 :]
+
+    if not p_first.startswith(b"1 0 obj\x0a<<\x0a"):
+        return False
+
+    p_first = p_first[11:]
+
+    signature = b"Euro-OfficeFORM"
+    index_stream = p_first.find(b"stream\x0d\x0a")
+    index_meta = p_first.find(signature)
+
+    if index_stream == -1 or index_meta == -1 or index_stream < index_meta:
+        return False
+
+    p_meta = p_first[index_meta:]
+    p_meta = p_meta[len(signature) + 3 :]
+
+    index_meta_last = p_meta.find(b" ")
+    if index_meta_last == -1:
+        return False
+
+    p_meta = p_meta[index_meta_last + 1 :]
+
+    index_meta_last = p_meta.find(b" ")
+    if index_meta_last == -1:
+        return False
+
+    return True