Java Modules default to stdlib namespace

[moehajj]

Problem or feature statement

Currently the LarkyEvaluator loads Java modules that are hardcoded in the ModuleSupplier without checking / forcing the intended namespace. It does, however, enforce that a VALID namespace is given. This may cause breaking changes in the future.

For example,
The following are currently valid:

load("@stdlib//re2j", "re2j") # expected (intended namespace given)
load("@vendor//re2j", "re2j") # unexpected (existing, yet unintended namespace given)

The following are currently invalid:

load("re2j", "re2j") # expected (namespace not given)    
load("@bla//re2j", "re2j") # expected (namespace does not exist)

Advised solution

Add namespace bins and getModules(namespace) capability to ModuleSupplier.

Testing scenarios

Only the following intended import should valid:

load("@stdlib//re2j", "re2j") # expected (intended namespace given)

The following should be invalid:

load("re2j", "re2j") # expected (namespace not given)    
load("@bla//re2j", "re2j") # expected (namespace does not exist)
load("@vendor//re2j", "re2j") # expected (existing, yet unintended namespace given