Similar to what was done with writers, readers also needed to be updated to match the new way of doing things.
This commits promotes a better DI (factories, injection through constructors).
This will improve the management of options and simplify some methods' signatures.
This commit will also help moving the code to a better state regarding Dependency Injection.
Added ODS writer
Refactored XLSX writer to abstract some pieces into an abstract multi-sheets writer
Created an abstract style helper
Moved shared components around
