scan_csv PanicException if quote_char is empty string

[cmdlineluser]

Checks

• I have checked that this issue has not already been reported.
• I have confirmed this bug exists on the latest version of Polars.

Reproducible example

import polars as pl
pl.scan_csv(b"", quote_char="")
# PanicException: index out of bounds: the len is 0 but the index is 0

Log output

No response

Issue description

Also happens for eol_char

pl.scan_csv(b"", eol_char="")
# PanicException: index out of bounds: the len is 0 but the index is 0

Not sure if comment_prefix needs a check for empty string also:

pl.scan_csv(b"a,b,c\n1,2,3", comment_prefix="").collect() # should be allowed?
# NoDataError: empty CSV

Expected behavior

No panic.

Installed versions

--------Version info---------
Polars:               1.9.0
Index type:           UInt32
Platform:             macOS-13.6.1-arm64-arm-64bit
Python:               3.12.2 (main, Feb  6 2024, 20:19:44) [Clang 15.0.0 (clang-1500.1.0.2.5)]

----Optional dependencies----
adbc_driver_manager:  <not installed>
cloudpickle:          <not installed>
connectorx:           <not installed>
deltalake:            <not installed>
fastexcel:            <not installed>
fsspec:               <not installed>
gevent:               <not installed>
great_tables:         <not installed>
hvplot:               <not installed>
matplotlib:           <not installed>
nest_asyncio:         <not installed>
numpy:                1.26.4
openpyxl:             <not installed>
pandas:               2.2.1
pyarrow:              15.0.2
pydantic:             <not installed>
pyiceberg:            <not installed>
sqlalchemy:           <not installed>
torch:                <not installed>
xlsx2csv:             <not installed>
xlsxwriter:           <not installed>