feat: contains and containsItems [DHIS2-16211]

[jimgrace]

This PR adds two expression functions:

contains(expr, ...) returns true if the first expr contains each of the following expressions as a substring.

containsItems(expr, ...) returns true if the first expr is split into tokens separated by commas, and each of the following expressions exactly matches one of the tokens.

See DHIS2-16211 for more details and examples.

@jbee Note that in ExpressionGrammar.kt the grammar is defined as:

        fn(NamedFunction.contains, expr, expr, expr.plus()),
        fn(NamedFunction.containsItems, expr, expr, expr.plus()),

I wanted to require two expression arguments and then have optional additional expressions. But this seemed to result in no expressions required, essentially the equivalent of:

        fn(NamedFunction.contains, expr.plus()),
        fn(NamedFunction.containsItems, expr.plus()),

As a result, these functions can be called with no arguments. Then when ExpressionFunctions contains(values: List<String?>) and containsItems(values: List<String?>) refer to values[0] they generate an IndexOutOfBoundsException, as is tested for in ContainsTest and ContainsItemsTest. I did not try to fix this because I didn't know how you would want to address the problem.

[vgarciabnz]

@jimgrace @jbee I have changed the base branch to beta just to trigger a beta build instead of a production build (there is no production release yet for the mulitplatform library).

[jbee]

I think I see the mistake with the function, I will update the PR

[jbee]

Closing if favor of #51 (I did not find how to make a PR to your PR without needing write access to your fork so I made a new PR)