feat: csvs into xlsx

[g-pechorin]

✨ Feature

PR Description

Adds functions to combine/split .csv files into .xlsx files.

Intention is to build a pipeline that;

• runs carrot-transform (et al) on the extracted data
• merges those .csv (or .tsv?) it into a .xlsx document
• run the .xlsx through existing shift_dates_inplace()
• split the .xlsx file into .csv / .tsv again
• upload those to the BC Insights

Related Issues or other material

Related #https://github.com/Health-Informatics-UoN/nuh-sql/issues/89
Closes #

Screenshots, example outputs/behaviour etc.

✅ Added/updated tests?

• This PR contains relevant tests / Or doesn't need to per the below explanation

[optional] What gif best describes this PR or how it makes you feel?

This feels surprisingly "clean" as an approach

[github-actions]

Coverage Report

File	Stmts	Miss	Branch	BrPart	Cover	Missing
nuh_helper/csv_xlsx
__init__.py	43	2	16	2	93%	19, 64
nuh_helper/date_shift
__init__.py	278	18	106	16	89%	149->158, 167, 255->253, 257->251, 376->390, 400->415, 402, 552, 578, 601, 614, 622–629, 665, 687, 691, 697
_excel.py	94	22	56	7	71%	27->26, 34, 124–137, 174, 207->213, 220–231
_parse.py	30	5	16	2	85%	31–40
nuh_helper/profile
__init__.py	178	2	54	2	98%	180->183, 255–256
TOTAL	643	49	252	29	89%

Tests	Skipped	Failures	Errors	Time
97	0 💤	0 ❌	0 🔥	8.980s ⏱️