[DMN Designer] Data Type Structure update is slow

The performance of dmn structures edit seems to be downgraded. Just adding another field into a existing structure takes ~5 seconds. The attached video demonstrates just saving added field however also other operations, like remove field performance was downgraded.

Acceptance test

• Define 5 simple data types
• Define 3 structures, each 3 fields, one is dependent on other two
• Invoke constraint dialog multiple times in a row, confirm changes, discard changes