Use fernflower as the default decompiler

[testforstephen]

This PR does the following:

• It replaces the default disassembler ClassFileBytesDisassembler with fernflower decompiler, which provides better decompilation results.
• It records the line mappings when decompiling class file, which is needed by the debugger to re-map the line numbers when a breakpoint occurs.

[testforstephen]

test this please

[testforstephen]

The failed test cases are random, unrelated to this PR changes.

[rgrunber]

For reference, https://github.com/JetBrains/intellij-community/tree/idea/231.9011.34/plugins/java-decompiler/engine#licence . However, I can't find anything at ClearlyDefined or https://gitlab.eclipse.org/eclipsefdn/emo-team/iplab/-/issues . We may will need to open an issue for approval on this.

Update: Additional concern from @fbricon , does this co-exist well with https://marketplace.visualstudio.com/items?itemName=dgileadi.java-decompiler (source) ? I think the extension gets priority over our "default" provider.

Filed at https://gitlab.eclipse.org/eclipsefdn/emo-team/iplab/-/issues/9099 .

[testforstephen]

For reference, https://github.com/JetBrains/intellij-community/tree/idea/231.9011.34/plugins/java-decompiler/engine#licence . However, I can't find anything at ClearlyDefined or https://gitlab.eclipse.org/eclipsefdn/emo-team/iplab/-/issues . We may will need to open an issue for approval on this.

@rgrunber Thanks for opening the IP issue for legal review.

Update: Additional concern from @fbricon , does this co-exist well with https://marketplace.visualstudio.com/items?itemName=dgileadi.java-decompiler (source) ? I think the extension gets priority over our "default" provider.

Yes, the built-in decompiler has the lowest priority. If you install the 3rd party decompiler extension, it will take precedence over the default one.

[rgrunber]

@fbricon mentioned something about a clash between the fernflower settings and the ones we set, but I'm not seeing it. The settings this PR sets are at https://github.com/eclipse/eclipse.jdt.ls/pull/2704/files#diff-18fc39092640259fd06479de72a5e1b47512bbf199c9373cc2362f0846b62906R68-R81 and they don't persist beyond the FernFlower instance created, which wouldn't be used if some 3rd part provider contributed a decompiler that took priority.

[testforstephen]

They don't share settings with each other. The 3rd party fernflower provider has a setting java.decompiler.fernflower for user to configure, while our built-in one does not support that but uses a default tuned settings. I believe most users don’t have knowledge on how to customize the decompiler settings. I will keep it as it is unless there is a feature request to custom the decompiler options.