Extend subdiv arg to accept multiple values

[arkid15r]

Add ability to request holidays for more than one entity's subdivision. Keep it backward compatible.

[Wedge009]

This sounds helpful. The categories and years parameters already accept multiple values. I was looking into this for my organisation that is spread across multiple Australian states. I think to work around the current lack of this feature I'll probably have to manually combine the holidays for each state into a set. Holidays given without any subdiv parameter are only holidays observed across the entire country.

[arkid15r]

I think I once started implementing this for v0 but I'm not sure if it'll make it there. Will definitely take another look for v1 support.

[Wedge009]

I managed to work around it as described above, but definitely a 'nice-to-have' feature.

[PPsyrius]

@arkid15r do we want to add this to #2345 ?

[arkid15r]

It seems (based on the label) I didn't plan to add it into v0 initially. I believe it can be done in a backward-compatible way so why not? @KJhellico @PPsyrius wdyt?

[PPsyrius]

I'm in favor of implementing them beforehand, maybe alongside a way to get all subdivisions as well - perhaps subdiv=ALL?

[KJhellico]

Why not? 👍

maybe alongside a way to get all subdivisions as well - perhaps subdiv=ALL?

It sounds interesting.