fix: correct a few typos, mostly in user facing strings

[Delapouite]

Hi Vitaly

While skimming through the codebase, looking to discover how hard it would be to implement Socket.io support as you mentioned in #21 (comment), I stumbled upon a few typos.

So here's a quick PR with the ones I found.

Thanks for this great tool.

[vi]

Note that in my mind Websocat v1 branch is marked as obsolete and it is more interesting for me to advance Websocat v3. But there are more unimplemented things than implemented in v3. Websocat v1 is legacy and Websocat v3 may require a solid week or two of concentrated efforts to get to production (and the more features get added to v1, the more distance v3 would need to go to get on par with v1).

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Maybe https://crates.io/crates/rust_socketio can be used to bring some more high-evel socketio support to Websocat.