Impacted versions:
Master branch, should by 12.0

Steps to reproduce:
Install a third party addon with localization po file in i18n folder, even loading translation manually, the translation won't work, The console reports error: Translation .... not found in reference pot, skipping.
Reverse the change of  "odoo/tools/translate.py" in this commit, the issue was gone.

Expected behavior:
The po translation works as before.



lineterminator = '\n'
csv.register_dialect("UNIX", UNIX_LINE_TERMINATOR)
def encode(s):
    assert isinstance(s, pycompat.text_type)
    return s
TRANSLATED_ELEMENTS = {
    'abbr', 'b', 'bdi', 'bdo', 'br', 'cite', 'code', 'data', 'del', 'dfn', 'em',
    'font', 'i', 'ins', 'kbd', 'keygen', 'mark', 'math', 'meter', 'output',
    'progress', 'q', 'ruby', 's', 'samp', 'small', 'span', 'strong', 'sub',
    'sup', 'time', 'u', 'var', 'wbr', 'text',
}
TRANSLATED_ATTRS = {
    'string', 'help', 'sum', 'avg', 'confirm', 'placeholder', 'alt', 'title',
}
avoid_pattern = re.compile(r"\s*<!DOCTYPE", re.IGNORECASE | re.MULTILINE | re.UNICODE)
node_pattern = re.compile(r"<[^>]*>(.*)</[^<]*>", re.DOTALL | re.MULTILINE | re.UNICODE)
def translate_xml_node(node, callback, parse, serialize):