Rework the module-info declarations to be fully open modules

[jponge]

There is little benefit from strong encapsulation at this stage.

Fixes #739

[jponge]

@cescoffier I propose to make open modules.

I see little benefit from strong encapsulation, but we can discuss this.
I think the following works if we want to limit visibility:

module io.smallrye.mutiny {

    requires org.reactivestreams;

    exports io.smallrye.mutiny;
    exports io.smallrye.mutiny.groups;

    exports io.smallrye.mutiny.helpers;
    exports io.smallrye.mutiny.helpers.test;
    exports io.smallrye.mutiny.helpers.spies;

    exports io.smallrye.mutiny.infrastructure;
    exports io.smallrye.mutiny.subscription;
    exports io.smallrye.mutiny.tuples;
    exports io.smallrye.mutiny.unchecked;

    uses io.smallrye.mutiny.infrastructure.MultiInterceptor;
    uses io.smallrye.mutiny.infrastructure.ExecutorConfiguration;
    uses io.smallrye.mutiny.infrastructure.UniInterceptor;
    uses io.smallrye.mutiny.infrastructure.CallbackDecorator;
}

[codecov]

Codecov Report

Merging #773 (da417a2) into main (6a72b91) will increase coverage by 0.31%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##               main     #773      +/-   ##
============================================
+ Coverage     89.90%   90.22%   +0.31%     
- Complexity     3007     3017      +10     
============================================
  Files           377      377              
  Lines         11883    11883              
  Branches       1497     1499       +2     
============================================
+ Hits          10684    10722      +38     
+ Misses          612      591      -21     
+ Partials        587      570      -17     

Impacted Files	Coverage Δ
...smallrye/mutiny/helpers/test/AssertSubscriber.java	89.47% <0.00%> (-0.76%)	⬇️
...tiny/operators/multi/MultiBufferWithTimeoutOp.java	75.63% <0.00%> (+0.84%)	⬆️
...allrye/mutiny/operators/uni/UniAndCombination.java	89.53% <0.00%> (+1.16%)	⬆️
...mallrye/mutiny/operators/multi/MultiFlatMapOp.java	86.76% <0.00%> (+1.53%)	⬆️
...mallrye/mutiny/helpers/queues/MpscLinkedQueue.java	91.93% <0.00%> (+1.61%)	⬆️
...java/io/smallrye/mutiny/helpers/Subscriptions.java	80.66% <0.00%> (+1.65%)	⬆️
...io/smallrye/mutiny/operators/uni/UniMemoizeOp.java	95.04% <0.00%> (+1.98%)	⬆️
...y/operators/multi/builders/IterableBasedMulti.java	84.04% <0.00%> (+2.12%)	⬆️
...operators/multi/builders/CollectionBasedMulti.java	96.77% <0.00%> (+3.22%)	⬆️
...subscription/SwitchableSubscriptionSubscriber.java	99.18% <0.00%> (+4.09%)	⬆️
... and 4 more

[cescoffier]

Look good to me. Open modules FTW!