Fix distinct return type to allow list operation chaining (finos#353)

Fix BP type resolution for ListOperations, and as-key code gen (finos…

…#351)

* Fix BP type resolution for ListOperations, and as-key code gen

* Remove debugging code

DSL syntax: sort, reverse, join, sum, min, max, first, last (finos#344)

* Introduce sort function. Clean up some warnings

* Added syntax tests and adjusted type inference

* Update test

* Fix isOutputListOfLists validation

* Format code

* Code gen for sort and reverse-sort

* Validation

* Reverse syntax instead of reverse sort

* Join, sum, min/max

* Add first, last and index keywords

* Null checks, more tests

* Rename to get-index and fix validation

* Try again with the validation

* Tidy up

* Remove get-item and remove-item for now

Co-authored-by: Dennis Huebner <dennis.huebner@gmail.com>

Xtext 2.25 / Eclipse 2021-12 upgrade (finos#348)

* Xtext 2.25 / Eclipse 2021-12 upgrade

* Fix dependencies

* Add tycho env

* Java target 8, resolve/ignore errors

* Tidy up

* Random attempts to fix things

* Add org.eclipse.xtext.xbase.feature.group

* More random stuff to make it stable

* Tidy up

* Uncomment inject

* Remove unused file

* classpath

* Update .classpath

* Update .classpath

* Update .classpath

* Update .classpath

* Update .classpath

* Fix test

Change constructor to public for backwards compatibility

Re-add static method for backwards compatibility

Tidy up Date and DateImpl (finos#347)

* Tidy up Date and DateImpl

* Access

Fix conditions and validators for type inhertiance (finos#346)

* Fix conditions for inherited types

* Fix separator

* Actually fix separators

* Fix for inherited conditions in different namespace

Add null check for ImportGenerator addExpression (finos#345)

DSL List reduce syntax (finos#343)

* Reduce function

* Reduce code gen, single cardinality map, and validation

* Reduce validation

* Organise imports

* Revert previous commit

* Organise imports