Apply `Options` configuration rules to parsing

[hrszpuk]

The Options.Rules.* need to apply to parsing and the reaction:

• [ ] AllowEmptyValues -> if false then error
• [ ] AllowEmptySections -> if false then error
• [ ] AllowNestedSections -> if false then treat nested sections as 'standard' sections. The nested symbol becomes part of the identifier.
• [ ] AllowSpacesInKeys -> if false then error
• [ ] AllowSpacesInValues -> if false then error
• [ ] AllowDuplicateKeys -> if true then use the last duplicate, if false then error
• [ ] AllowDuplicateSections -> if true then use the last duplicate, if false then error
• [ ] IgnoreCaseSensitivity -> if true then case fold to lowercase
• [ ] IgnoreDelimiterPadding -> if true then any whitespace around the delimiter is ignored, otherwise, if false, it becomes a part of the key/value.
• [ ] IgnoreSectionNamePadding -> if true then any whitespace around the section name is ignored, otherwise, if false, it becomes a part of the section name.
• [ ] IgnoreValueQuotes -> if true then the quotes around values, "value", are ignored (value), otherwise, if false, the quotes become part of the value ("value" will be "value" not value.)

[hrszpuk]

After going over how these may differ for parsing/serialisation I'm leading towards separating them in the Options struct again. Ah, it is simpler to have the same bool for both parsing and serialisation, but I feel like it might be easy to misinterpret some, and some doing even make sense for both cases (e.g. IgnoreDelimiterPadding doesn't apply to serialisation since it wouldn't ignore something it is generating? ).