Add column width settings

[Slamdunk]

Related to #129 & #866

Automatic width calculation seems to me a bit overwhelming from a maintainer perspective.

Static width settings should be enough for the majority of use cases.

I'm not used to ODS format: if this PR gets approved, I'll try to implementing this in ODS too.
Feedback required.

[CLAassistant]

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[Slamdunk]

There is nothing I can click con the CLA page, so I don't know what I have to do:

[Slamdunk]

Just seen #715