Support integer literals in range expression of for loops.

## `generator`
Support integer literals in range expressions of for loops and allow variable usage in count part of write statement.  

The changes are downwards compatible and resolve #120 "Dynamic sample size in for-loops".

Changelog: changed

Implements a new pipeline component that uses a surrogate model to predict data.

Solves #117

This commit resolves issue #116 "ClassCastException when setting integer value for σ in noise-data component."

Reworked the handling of DSL files for developers. The `LanguageHelper` component was renamed to `AttributeHelper` and is more powerful than the old version. The function `lookup` automatically does default value handling (using default values of the attribute definition if the attribute is missing in the DSL) and automatic type casts. Thus, `int` values are now automatically casted into `double` values if the attribute definition states that the attribute is of type `real`.

Changelog: changed

Lauren Paul authored 7 months ago and Bernhard Johannes Berger committed 7 months ago

1) `Requirements.requireProbability` checked the wrong upper bound
2) `constraint`, `correlated` and `ranged` statistics used wrong CDI names
3) The `correlated` statistics writer also logged the fitness values of other fitness calculation strategies. This was removed.

Closes #93

Changelog: bug

Closes #86

Added regression tests for all surrogate models provided by `surrogate.simple` and `surrogate.smile`. Fixed minor bugs that prevented regression tests to work.

Closes #84
Resolve "Create regression tests for surrogate functions"