feat(#2640): added snippet test for horizontal abstract syntax

[maxonfjvipon]

Closes: #2640

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PR-Codex overview

This PR focuses on adding test resources and snippets for simple-horizontal and complex-horizontal in the eo-maven-plugin.

Detailed summary

• Added test resource for simple-horizontal.yaml
• Added expected output for simple-horizontal.yaml
• Added file path for simple-horizontal.eo
• Added arguments for simple-horizontal.eo
• Added eo code for simple-horizontal.eo
• Added test resource for complex-horizontal.yaml
• Added expected output for complex-horizontal.yaml
• Added file path for complex-horizontal.eo
• Added arguments for complex-horizontal.eo
• Added eo code for complex-horizontal.eo

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[maxonfjvipon]

@yegor256 please have a look

[yegor256]

@maxonfjvipon it's too simple. Let's make it more complex, to see a number of named attributes on the same line:

+package simple
+alias org.eolang.io.stdout
+alias org.eolang.io.sprintf

[args...] (stdout msg > @) (sprintf "Hello, %s!" name > msg) ("Jeff" > name) > main

[maxonfjvipon]

@yegor256 please have a look one more time

[yegor256]

@maxonfjvipon will merge after this one is fixed: #2660

[yegor256]

@maxonfjvipon I'm ready to merge this one, but I'm sure it won't work because of varargs inside. Please, fix it.

[maxonfjvipon]

@yegor256 please have a look

[yegor256]

@rultor merge

[rultor]

@rultor merge

@yegor256 OK, I'll try to merge now. You can check the progress of the merge here

[rultor]

@rultor merge

@yegor256 Done! FYI, the full log is here (took me 21min)