[SyntaxTree] Add support for `CallExpression`

* Generate `CallExpression` syntax node for all semantic nodes inheriting from
`CallExpr` with call-expression syntax - except `CUDAKernelCallExpr`.
* Implement all the accessors
* Arguments of `CallExpression` have their own syntax node which is based on
the `List` base API

Differential Revision: https://reviews.llvm.org/D86544