Configured Midsummer Eve and Christmas Eve as unofficial holidays for Finland

[auguchanan]

No description provided.

[auguchanan]

In Finland Midsummer Eve and Christmas Eve are not universal holidays as the law does not define them as holidays. Instead most of the collective agreements that have been negotiated between the employer and employee unions define these as holidays. However, not all of the collective agreements contain such definitions and hence they are not universal holidays.

I wanted to somehow reflect this fact in the information returned by the library and looking at the source code designating the holidays in question as unofficial holidays seemed like a natural solution, but if the unofficial holiday designation is intended for some other use cases and some other approach would be more applicable here, I am open to suggestions for creating a better implementation.