fix(hana): Allow custom fuzzy search cqn

[BobdenOs]

With the old database service it was possible to define a custom fuzzy search cqn.

The test implements it like:

{
  func: 'CONTAINS',
  args: [
    { list: [{ ref: ['ID'] }, { ref: ['NAME'] }] },
    { val: hanaSearchTerm },
    { func: 'FUZZY', args: [{ val: 0.8 }, { val: 'similarCalculationMode=searchCompare' }] }
  ]
}

But according the HANA documentation this is incorrect. As CONTIANS is not a function it is actually a predicate. Which would be defined like:

{
  xpr: [
    'CONTAINS',
    {
      xpr: [
        { list: [{ ref: ['ID'] }, { ref: ['NAME'] }] },
        { val: hanaSearchTerm },
        'FUZZY',
        {xpr: [[{ val: 0.8 }, { val: 'similarCalculationMode=searchCompare' }]]}
      ]
    }
  ]
}

Additionally the contains function from the OData spec clashes with the HANA internal function name. Which means that the custom code has to adjust the function name to CONTAINS to avoid the function from being rewritten into the OData spec compliant variant.