Trailing whitespaces at the beginning of character records are removed

[theCapypara]

At the moment the crate removes trailing whitespaces at the beginning of character fields. This is probably fine in most cases, but sometimes there might be a reason for these trailing whitespaces. While trailing whitespaces at the end of a string are padding, those at the beginning are not.

The dbase spec states for character fields:

Symbol	Data Type	Description
C	Character	All OEM code page characters - padded with blanks to the width of the field.

(https://www.dbase.com/Knowledgebase/INT/db7_file_fmt.htm)

[tmontaigu]

This means we probalby need to pass down an option in the Reader to chose whether these leading whitespace should be trimmed or not, or change the behavior without an option 🤔

[tmontaigu]

'Fixed' by #59