[BUG] TCP metadata filter should be prepared for unhappy data paths

[bonifaido]

Description

Currently the TCP metadata Proxywasm filter (Rust -> Wasm) is "optimized" for the happy path of data packages. It crashes when the incoming byte array is not enough long for example. Also there are too much unconditional unwraps.

Expected Behavior

It should be working under any circumstances, these issues should be reviewed and handled.

Actual Behavior

Please describe what happened instead.

Affected Version

Please provide the version number where this issue was encountered.

Steps to Reproduce

1. First step
2. Second step
3. etc.

Checklist

• I have read the contributing guidelines
• I have verified this does not duplicate an existing issue