Deprecate unnecessary unescaping of tags

[kornelski]

Fixes #341

[codecov-commenter]

Codecov Report

Merging #397 (8ba26d4) into master (e701c4d) will increase coverage by 0.06%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #397      +/-   ##
==========================================
+ Coverage   61.37%   61.44%   +0.06%     
==========================================
  Files          20       20              
  Lines       10157    10157              
==========================================
+ Hits         6234     6241       +7     
+ Misses       3923     3916       -7     

Flag	Coverage Δ
unittests	61.44% <ø> (+0.06%)	⬆️

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Impacted Files	Coverage Δ
src/events/mod.rs	73.96% <ø> (ø)
src/lib.rs	26.00% <0.00%> (ø)
src/reader.rs	87.51% <0.00%> (+0.09%)	⬆️
src/de/mod.rs	75.73% <0.00%> (+0.55%)	⬆️

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[Mingun]

I think, we need to remove that function entirely if is does the wrong thing. I'll hold this PR for a while, because I also prepare a PR that touches many of escaping/decoding functions and I need time to review this and find an initial PR that introduces it to understand what problem it solves.

Anyway, you feel free to change this PR to remove method and update a Changelog.md. Could you also use #118 instead of #341 in messages and in the changelog?

[kornelski]

I've hidden these functions from docs, so that they're almost as good as deleted, but don't need semver-major bump. You could delete them next time you release a major version.

[Mingun]

We're anyway at 0.x stage so any release is breaking and I do not limit myself in using this opportunity. Actually, next 0.24.0 release already contains breaking changes, so one more is not a problem. In any case, we should remove any usage of deprecated items from our codebase