add EditionDisplay to give human readable names to chapter editions

[robUx4]

When there are multiple editions it should make it easier to pick one for the user.

Otherwise tags with TagEditionUID as the target might be sufficient and more versatile.

Fixes #300

[hubblec4]

Which edition name(string) should be used if there is an EditionDisplay and a Tag? Has the TagString from the SimpleTag a higher priority? Or should the Tag fully ignored if an EditionDisplay exists?

[robUx4]

Which edition name(string) should be used if there is an EditionDisplay and a Tag? Has the TagString from the SimpleTag a higher priority? Or should the Tag fully ignored if an EditionDisplay exists?

I created #655 to fix this issue which also exists for other elements and needs to be handled independently from this PR.

[robUx4]

Merging this as it's for Matroska v5 and won't affect the specs of Matroska v1 ot v4.