[ADQL] Add `UPPER(...)`

src/adql/parser/ADQLQueryFactory.java

src/adql/parser/feature/FeatureSet.java

src/adql/parser/feature/default_features.md

src/adql/parser/grammar/adqlGrammar201.jj

src/adql/query/operand/function/string/UpperFunction.java

src/adql/translator/ADQLTranslator.java

src/adql/translator/JDBCTranslator.java