test input issues for NumberFormatter / ICU4J

[echeran]

Some of these issues are a part of the test framework (ex: schema definition), some might be related to the ICU4J executor, some might be for the ICU4J NumberFormatter APIs.

• the types of the enum values for groupingStrategy are not homogeneous. This caused a problem for the ICU4J executor when handling the parsed value, requiring a workaround to stringify the parsed value followed before conversion to an enum was possible.
• the names of the enums for groupingStrategy don't match the enum names for NumberFormatter.GroupingStrategy.
• does ICU4J support halfCeil or halfFloor? It is not a part of java.math.RoundingMode
• notation should be an enum instead of an open ended string
• how do you use currencyDisplay in ICU4J NumberFormatter?
• Update test data generator to skip tests with roundingMode = exact
• Fix bugs in test data generation for skeleton values not fully matching the provided options