Unable to handle hidden rows when attribute value of 'hidden' is 'true' in some xlsx files

[rockc2020]

When I run xlsx2csv against some xlsx files, found hidden rows are exported to the csv files even if the parameter skip_hidden_rows is true by default.

After digging into it a bit, I noticed those xlsx files have set the attribute value of hidden to true instead of 1 as some others. This caused the condition checking code here not filtering the hidden row out.

        elif self.in_sheet and (name == 'row' or (has_namespace and name.endswith(':row'))) and ('r' in attrs) and not (self.skip_hidden_rows and 'hidden' in attrs and attrs['hidden'] == '1'):

Here is an example xlsx file attached which is exported from Lark docs (https://www.larksuite.com/en_us/product/creation?from=hero_section)
feishu_test_hidden_rows.xlsx

Here are the hidden row attributes from xlsx files exported from MS Excel and Google Docs:

row {'r': '3', 'hidden': '1'}

Here are the hidden row attributes from xlsx files exported from larksuite:

row {'customHeight': 'true', 'hidden': 'true', 'ht': '19', 'r': '2'}

Let me know if you'd like to include it. If yes, I'd be happy to raise a PR for it.