Warnings (and maybe errors) are reported in unstable order
This can be demonstrated by test `encoding_str_warnings` which is failed with the following message:
```
[info] - encoding_str_warnings *** FAILED ***
[info]   encoding_str_warnings.ksy: /seq/1/encoding:
[info]   	warning: use canonical encoding name `UTF-8` instead of `utF-8` (see https://doc.kaitai.io/ksy_style_guide.html#encoding-name)
[info]   
[info]   encoding_str_warnings.ksy: /seq/2/encoding:
[info]   	warning: use canonical encoding name `ISO-8859-1` instead of `latin1` (see https://doc.kaitai.io/ksy_style_guide.html#encoding-name)
[info]   
[info]   encoding_str_warnings.ksy: /instances/alias/encoding:
[info]   	warning: use canonical encoding name `ISO-8859-1` instead of `ISo8859-1` (see https://doc.kaitai.io/ksy_style_guide.html#encoding-name)
[info]   
[info]   encoding_str_warnings.ksy: /instances/wrong_case/encoding:
[info]   	warning: use canonical encoding name `ISO-8859-1` instead of `iSo-8859-1` (see https://doc.kaitai.io/ksy_style_guide.html#encoding-name)
[info]    did not equal encoding_str_warnings.ksy: /seq/1/encoding:
[info]   	warning: use canonical encoding name `UTF-8` instead of `utF-8` (see https://doc.kaitai.io/ksy_style_guide.html#encoding-name)
[info]   
[info]   encoding_str_warnings.ksy: /seq/2/encoding:
[info]   	warning: use canonical encoding name `ISO-8859-1` instead of `latin1` (see https://doc.kaitai.io/ksy_style_guide.html#encoding-name)
[info]   
[info]   encoding_str_warnings.ksy: /instances/wrong_case/encoding:
[info]   	warning: use canonical encoding name `ISO-8859-1` instead of `iSo-8859-1` (see https://doc.kaitai.io/ksy_style_guide.html#encoding-name)
[info]   
[info]   encoding_str_warnings.ksy: /instances/alias/encoding:
[info]   	warning: use canonical encoding name `ISO-8859-1` instead of `ISo8859-1` (see https://doc.kaitai.io/ksy_style_guide.html#encoding-name) (SimpleMatchers.scala:34)
```

The reason because `/instances/wrong_case` and `/instances/alias` instances reported in different order in expected message and by the compiler.

[`flatMap` here](https://github.com/kaitai-io/kaitai_struct_compiler/blob/6ac72529b55b89d749127279da9cdd34545c1672/shared/src/main/scala/io/kaitai/struct/precompile/CanonicalizeEncodingNames.scala#L13-L18) traverses maps in order that the map provides, and default `Map` implementation is unordered.