Xlsx style cell column

[gpibarra]

Description

Currently, you can style the header and the rest of the cells (separately). This PR allows you to format each of the exported columns (value cells only; header row cells are not included).
When you style a column, you can call the function multiple times, and each style (or callback) is saved in an array. When obtaining the column style, all styles are calculated and merged. This is designed to allow styling, for example, in the make/setup function for potential new column classes that extend the ExportColumn class.
Styles (or callbacks) can be fixed, meaning they do not depend on the cell value. They will be cached to improve performance and avoid merging each row of data in the export file. Additionally, you can assign a style based on the cell value, which will be executed on each row of data (OpenSpout does not support Excel conditional formatting).

Functional changes

• Code style has been fixed by running the composer cs command.
• Changes have been tested to not break existing functionality.
• Documentation is up-to-date.

[gpibarra]

In the documentation, I corrected a change to this PR: #16025
It wasn't clear whether the function needed to be renamed or not, but only the documentation had been changed. Feel free to rename the function.

[danharrin]

To be honest I am concerned about the performance implications of calling another method for each cell. Maybe the implementation should just be makeXlsxRow() static method on the Exporter where you can pass a function that accepts $data, $style, $columns and returns a Row object. The $columns would be an array of column names that match the $data in order, so you can use Row::fromValuesWithStyles() yourself. If that function is not passed, the makeXlsxRow() would just return the default Row::fromValues() object. This way, we aren't really introducing new overhead by looping over columns etc. Thoughts?

[danharrin]

At this point, maybe the entire writer creation process should just be moved onto the Exporter class, so it can be overriden in any way instead of needing all these new config methods

[gpibarra]

I agree. Initially, I only called getStyle once before the record loop. But the fact that the library doesn't support conditional formatting motivated me to create an additional method. I think it's perhaps too much customization for the default case. I would leave the basic style and not the one that depends on the value (called for each cell in each row).

Regarding the writer depending on the exporter, I don't see it as a problem, but if not, it's not that difficult to override the logic. These changes I proposed were born from a project with Filament v3, and I modified the writer logic with a bind from a service provider. It's not complicated.

[danharrin]

Can yon move all the writer logic into the exporter class then please? We could even remove that configureXlsxWriterBeforeClose() method tbh