Avoid copying IR nodes when no change is performed in passes

[hubertp]

Pull Request Description

This PR attempts to avoid creating unnecessary IR nodes. Whenever none of the components of any IR node is different from the original one, there is no need to create a new instance of it.

Renders #10718 obsolete.

Important Notes

I spent quite a lot of time debugging problems with this approach (compared to #10718) only to find out that the problem was in the overriden definition of MetadataStorage.equals, that prevented duplication from working correctly.

Checklist

Please ensure that the following checklist has been satisfied before submitting the PR:

• The documentation has been updated, if necessary.
• Screenshots/screencasts have been attached, if there are any visual changes. For interactive or animated visual changes, a screencast is preferred.
• All code follows the
  Scala,
  Java,
  TypeScript,
  and
  Rust
  style guides. In case you are using a language not listed above, follow the Rust style guide.
• Unit tests have been written where possible.

[JaroslavTulach]

There is a runtime-parser test failure:

Same expected: org.enso.compiler.core.ir.Module<
Module(imports = List(), exports = List(), bindings = List(), location = None, passData = MetadataStorage[], diagnostics = DiagnosticStorage(diagnostics = List()), id = null)
> but was: org.enso.compiler.core.ir.Module<
Module(imports = List(), exports = List(), bindings = List(), location = None, passData = MetadataStorage[], diagnostics = DiagnosticStorage(diagnostics = List()), id = null)
>

as I discovered later this is probably due to difference of MetadataStorage and DiagnosticStorage, right?

[JaroslavTulach]

Magnificent work on the copy methods rewrite. They should have been generated... if we ever get to rewriting this to Java, please use annotation processor to generate these copy & co. methods.

[hubertp]

I can't get flamegraphs similar to #9236 (comment) working but I've noticed in our profiling that we do much less copying now. At the expense of more equality checks, so you give some and you take some.
But this PR has already grown a lot and it seems to be a step in a good direction.