Refactor to JCTools

[jponge]

Replace existing MPSC / SPCS queue implementations by using JCTools

[jponge]

Todo:

• Review the selected queue variants
• Possibly use specialised variants through the Queues abstraction (e.g., *Unpadded* if Unsafe can be loaded, etc)
• Make sure we don't use any implementation that doesn't work in native
• Will need a JCTools 4.0.2 with JPMS module info
• Shading? Could be an option, but JPMS modules will likely be a blocker (Mutiny module requires JCTools to compile, but then if it's shaded it must not be in the module-info anymore) ➡️ won't do, there's a next JCTools release with JPMS

[codecov]

Codecov Report

Merging #1334 (5a45a72) into main (70f0f52) will increase coverage by 0.14%.
Report is 7 commits behind head on main.
The diff coverage is 79.78%.

❗ Current head 5a45a72 differs from pull request most recent head 994e55b. Consider uploading reports for the commit 994e55b to get more accurate results

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #1334      +/-   ##
============================================
+ Coverage     88.77%   88.92%   +0.14%     
+ Complexity     3342     3266      -76     
============================================
  Files           459      456       -3     
  Lines         13438    13218     -220     
  Branches       1655     1640      -15     
============================================
- Hits          11930    11754     -176     
+ Misses          840      813      -27     
+ Partials        668      651      -17     

Files	Coverage Δ
...n/java/io/smallrye/mutiny/groups/MultiFlatten.java	100.00% <100.00%> (ø)
...e/mutiny/operators/multi/MultiCombineLatestOp.java	86.02% <100.00%> (+0.07%)	⬆️
...smallrye/mutiny/operators/multi/MultiEmitOnOp.java	92.38% <100.00%> (ø)
...mallrye/mutiny/operators/multi/MultiGroupByOp.java	83.25% <100.00%> (ø)
...smallrye/mutiny/operators/multi/MultiWindowOp.java	91.66% <100.00%> (ø)
...ny/operators/multi/builders/EmitterBasedMulti.java	94.33% <100.00%> (ø)
...y/operators/multi/processors/UnicastProcessor.java	95.68% <100.00%> (ø)
...smallrye/mutiny/infrastructure/Infrastructure.java	71.75% <95.83%> (+2.01%)	⬆️
...erators/multi/builders/BufferItemMultiEmitter.java	89.87% <93.75%> (-0.92%)	⬇️
...rators/multi/overflow/MultiOnOverflowBufferOp.java	83.62% <80.00%> (-0.46%)	⬇️
... and 1 more

... and 11 files with indirect coverage changes

[jponge]

Note: this scratchpad branch will never be merged, a clean commit will be eventually done

[franz1981]

Few more comments, mostly naming, really, so feel free to ignore

[jponge]

Work continues in #1413, thanks again @franz1981