feat: support multiple bom poms

[maxandersen]

ShrinkWrap does not have direct support for multiple pom files to use
for resolving versions for dependencies without version, i.e. called
<dependencyManagement> in Maven, platforms in Gradle.

To fix it we now generate a temporary pom.xml that has nothing but a
section containg the list of managed pom dependencies.

This has the following consequences:

• we need to write a temporary file as ShrinkWrap does not allow passing a string directly.
• we avoid loading a bom pom as a pom which will activate parent poms features like adding repositories that generated warnings. Now this just don't happen.
• means that @pom references now can come in any order (before we required it to be the first)
• consequence of that is there in effect will be to //DEPS lists; one is pom's other is everything else.
• Also could resolve in change in behavior but as users only could load one pom.xml for this in past this should not be a problem;except maybe we don't generate so many warnings anymore if parent pom's were incomplete.

...and what this enables:

• having multiple bom poms which in particular is useful with larger frameworks like quarkus, springboot, groovy, kotlin which all rely on multiple boms.

Fixes #877

[maxandersen]

note, this really need some more manual/automatic testing before we merge it.

things to test:

• using multiple boms with quarkus 2+
• does jbang edit generate proper gradle file when using multiple boms?
• example from camel?

[codecov]

Codecov Report

Merging #1173 (9b4e955) into main (e416516) will increase coverage by 0.09%.
The diff coverage is 89.28%.

@@             Coverage Diff              @@
##               main    #1173      +/-   ##
============================================
+ Coverage     58.98%   59.07%   +0.09%     
- Complexity     1050     1052       +2     
============================================
  Files            84       84              
  Lines          5554     5569      +15     
  Branches        935      935              
============================================
+ Hits           3276     3290      +14     
- Misses         1795     1797       +2     
+ Partials        483      482       -1     

Flag	Coverage Δ
Linux	57.90% <89.28%> (+0.09%)	⬆️
Windows	57.82% <89.28%> (+0.09%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...in/java/dev/jbang/dependencies/DependencyUtil.java	81.33% <89.28%> (+1.33%)	⬆️

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