More improvements on WAV parser

[linkyndy]

The changes recently introduced (v2.9.0) are too eager and forgiving, meaning that the reading budget almost always gets exceeded for large files. In this iteration we focus on:

• making sure we detect the file as WAV, regardless of how much metadata can be read
• ignoring the fact chunk and solely relying on fmt and data to extract/compute the metadata
• reading as few bytes as possible rather than doing a thorough job extracing/computing all metadata according and not according to the format spec

[rcpalacio]

👍

[RubenWolff-wt]

lgtm