`AudioStreamWAV` missing `has_loop()` override

### Tested versions

4.7 dev

### System information

Windows 10

### Issue description

There is inconsistency in how different `AudioStream` implementations handle looping information. While formats like MP3 and OggVorbis implement the `loop` property and `has_loop()` method, `AudioStreamWAV` lacks this implementation entirely. Instead, it relies on a unique `loop_mode` property.

Because `AudioStreamWAV` does not override the virtual `has_loop()` method from the base `AudioStream` class, it always returns the default value (false), even when the WAV file is set to loop.

Some engine systems work with the base `AudioStream` class and rely on its common interface to determine stream behavior. The absence of a proper `has_loop()` override in the WAV implementation leads to logical failures in these systems.
Example:
In the `AudioStreamInteractive`. When performing a transition from a looping WAV track without a fade (see issue: #117855)

### Related Issue:
This problem is directly causes the behavior described in:
Issue #117855

### Steps to reproduce

See Issue: #117855

### Minimal reproduction project (MRP)

See Issue: #117855

Start by inspecting the AudioStream base interface and comparing the AudioStreamWAV implementation with the MP3 and OggVorbis implementations. Review AudioStreamInteractive and related issue #117855 to understand the failing transition behavior. Done means base AudioStream callers can correctly detect looping WAV tracks; verify with the reproduction from issue #117855.

Written by the indexing model from the issue text.