[Feature] Align sibling attributes

Thanks for the project! Super useful for some XML files I'm working with. Unfortunately, I cannot change the existing style of all the files, so I am looking for a way to auto-format new XML files to match the existing style. vscode-xml gets 99% of the way there, but I need to be able to align matching attributes of siblings. For example this:

<parent>
  <child  attribute1="some long value" attribute2="value2" attribute3="value3"/>
  <child attribute1="value1" attribute2="some other long value" attribute3="value3" />
</parent>

Should get formatted to this:

<parent>
  <child attribute1="some long value" attribute2="value2"                attribute3="value3"/>
  <child attribute1="value1"          attribute2="some other long value" attribute3="value3" />
</parent>

Note:

• All attributes on the same line (I don't like it either, but I can't change the existing style)
• attributes are aligned with spaces
• One space between the final " and the start of the next attribute.
• Just to stress this point, I cannot change the style. I cannot use the formatting style where each attribute is on a newline. Each attribute must be on the same line.

This feature would be a huge boon to have.

The issue provides before-and-after XML examples but names no source files or tests. Start by locating the XML formatter entry point and existing formatting tests, then determine how sibling attributes are represented. Done means matching attributes on sibling elements are aligned with spaces while remaining on the same line.