[load] read file with d3p1 namespace

[JanMarvin]

Allows reading the file shared in tidyverse/readxl#736 by @hidekoji. The xml scheme is somewhat inconsistent. For instance it is mixing all lower case letters and camel case:

• in [content_types.xml] there is a reference to sharedStrings.xml, the same is in /xl/_rels/workbook.xml.rels
• in xl/ there is sharedstrings.xml
• there is also a custom xml namespace d3p1 available in workbook.xml

There might be other shenanigans with these type of files, after all this only contains two worksheets with data. It looks like some Japanese finance data, at least I can read IFRS? So far there is only this single file available, therefore not sure that I will merge this.

library(openxlsx2)
url <- "https://www.dropbox.com/scl/fi/jirejqyyxig0cikk6i2bn/P_P1.xlsx?rlkey=iwhm91t9npo40596me1lewls8&dl=1"
wb <- wb_load(url)
wb_to_df(wb, sheet = 2) %>% .[seq_len(5), seq_len(5)]
#>           NA NA.1         NA.2               NA.3 日経会社コード
#> 2 カネコ種苗    P セグメント１ 連結優先(IFRS優先)        0021804
#> 3 カネコ種苗    P セグメント２ 連結優先(IFRS優先)        0021804
#> 4 カネコ種苗    P セグメント３ 連結優先(IFRS優先)        0021804
#> 5 カネコ種苗    P セグメント４ 連結優先(IFRS優先)        0021804
#> 6 カネコ種苗    P セグメント５ 連結優先(IFRS優先)        0021804