Added respecting the existing charset / newline

[nahsra]

No description provided.

[aldrinleal]

Focus on the feature/multi-pom-support as it adds a bit more complexity - bear in mind most of the formatting aspects, pom-wise, are actually covered to the point we only hand you back byte[]s to write back - if you see something missing let me know.

[aldrinleal]

Here's the kicker: POMOperator itself also detects both charsets and newlines (and trailing newline if thats the case) - for each and every file. They're held inside an instance of POMDocument - at the codemodder level, we only return bytes to be written

there's another problem: In the newer version of POMOperator, it might output several files at once - I suggest you target against the feature/multi-pom-support branch instead.

[aldrinleal]

btw here's the relevant snippet:

https://github.com/pixee/pom-operator/blob/master/src/main/java/io/github/pixee/maven/operator/FormatCommand.kt

[nahsra]

Closing this PR as the pom-operator upgrade helped solves this problem and we added tests to cover as well.