Extract a real core error from CoreError for the Sentry Reporter

[drew2a]

This PR closes #7066 by adding the last_core_output argument for the function SentryReporter.send_event().
If this argument is presented, then a Sentry Event will be formatted in the following way:

    def send_event(self, event: Dict = None, post_data: Dict = None, sys_info: Dict = None,
                   additional_tags: List[str] = None, last_core_output: Optional[str] = None):
   
        ...

        # try to retrieve an error from the last_core_output
        if last_core_output:
            reporter['last_core_output'] = last_core_output.split('\n')
            if last_core_exception := parse_last_core_output(last_core_output):
                exceptions = event.get(EXCEPTION, {})
                gui_exception = get_last_item(exceptions.get(VALUES, []), {})
                core_exception = {'type': last_core_exception.type, 'value': last_core_exception.message}
                delete_item(gui_exception, 'stacktrace')

                exceptions[VALUES] = [gui_exception, core_exception]

        ...

Where parse_last_core_output is

_re_search_exception = re.compile(r'^(\S+)\s*:\s*(.+)')
_re_remove_sentry = re.compile(r'Sentry is attempting.*')

@dataclass
class LastCoreException:
    type: str
    message: str


def parse_last_core_output(text: str) -> Optional[LastCoreException]:
    def _clean_up(s: str):
        return _re_remove_sentry.sub('', s).strip()

    for line in reversed(text.split('\n')):
        if m := _re_search_exception.match(line):
            return LastCoreException(type=_clean_up(m.group(1)),
                                     message=_clean_up(m.group(2)))
    return None

The new Sentry Event: https://sentry.tribler.org/organizations/tribler/issues/1747