Detect untrusted input used to make a call

### Describe the desired feature

A common way a contract can be made vulnerable is to make a call with attacker-controlled target and data. For example, see [this Li.Fi exploit](https://x.com/AlexSmirnov__/status/1813224734475116643).

Slither could detect that the arguments to `.call` are untrusted and flag it as a warning.