Re-introduce workspace reverse options from devonfw-ide

[jan-vcapgemini]

As an IDE user e.g. intellij, eclipse etc. of IDEasy I need the possibility to reverse the changes being done on my workspace by the settings merger.

In our legacy product devonfw-ide we had the options see: https://github.com/devonfw/ide/blob/9efaf926f1daa4e1e37a22fc89081255fbf55dab/documentation/configurator.asciidoc#how-to-customize:

• ws-up[date] to update workspace
• ws-re[verse] to reverse merge changes from workspace into settings
• ws-reverse-add to reverse merge adding new properties

We need to analyze these options, rename and re-implement them into our IdeToolCommandlet.
Keep in mind that we don't add options after the actual commandlet but instead we add them before them now e.g. ide my-option intellij

[hohwille]

I recently came across the internal implementation details of our XmlMerger and during my refactoring I hit the code for reverseMerge of XML files:
It was simply wrong and so I entirely removed it and replaced it with throw new UnsupportedOperationException.
But here is the thing:
Already implementing a generic XML merger was very complex.
The reverse merge operation is even way more complex.
Yet, the business value of reverse-merging is questionable.
I bet that we cannot find 10 or more people on this planet who really ever used this feature in devonfw-ide.
Actually I as most probably the ultimate power-user of devonfw-ide and IDEasy with the most projects and most complex setups do not use the feature any more since I get better success with manual steps.
IMHO this feature is a nice idea but it is somehow flawed by design.
It would actually be better to create a quality documentation and/or video how to solve this manually:

• backup your IDE config from main workspace
• launch your IDE in main workspace
• do the desired changes
• run a recursive diff of the new workspace config with the backup (e.g. in a graphical diff tool like WinMerge)
• Once you found the desired changes in the workspace config, simply apply them manually to your workspace templates in the project's settings

I would vote to entirely remove the reverseMerge method up to EnvironmentVariables and simplify our codebase (KISS).