#3289 Union flag options are bugged in independence flag editor

[Wuzzy]

When you design the flag when declaring independence, I noticed some bugs with how the flag editor behaves:

Namely, the union shape/position sometimes leads to weird results with the following combinations:

• Union shape triangle creates a weird broken triangle at the left which is partially cut-off for the union positions Center, Middle and Canton
• The union shapes rhombus, bend and chevron ignore the union position, however, the stars still respect it

Also, there are union positions named "Center" and "Middle" which is confusing. These refer to the horizontal and vertical center, perhaps this should be clarified

Version: 0.13.0 and 0.13.0+dev (commit Version: 0.13.0 and 0.13.0+dev).

[Wuzzy]

Note: The commit version I used was: cb10784763ce2a594dc5333ba83a56e197bc4e19