Allow specifying which Nodes require the global read lock

[marcphilipp]

Implementations of HierarchicalTestEngine can now specify which nodes
require the global read lock by overriding the new
Node.isGlobalReadLockRequired() method to return false.

This allows for more fine-grained locks when intermediate container do
not have any behavior of their own and thus do not require even the
global read lock.

Resolves #2982.

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Definition of Done

• There are no TODOs left in the code
• Method preconditions are checked and documented in the method's Javadoc
• Coding conventions (e.g. for logging) have been followed
• Change is covered by automated tests including corner cases, errors, and exception handling
• Public API has Javadoc and @API annotations
• Change is documented in the User Guide and Release Notes

[marcphilipp]

@leonard84 I'd also appreciate your opinion, if you have time to take a look.

[mpkorstanje]

LGTM. Tested with the original reproducer and an upgraded Cucumber, now works as intended.