test: Add E2E test and enhance simulator flexibility

[georgi-l95]

Description:
This PR adds new functionality aimed at making the simulator a better and more flexible test driver for E2E tests. It achieves this by:

• Adding a new StreamStatus data object, which collects and stores information about the recently published/consumed blocks, as well as the latest statuses.
• Exposing the necessary methods to make this usable in other modules, primarily the E2E Tests module.
• Adding a new E2E test that covers the positive scenario where the simulator sends blocks to the Block Node, which responds with the correct response.
• Adds a new CustomThreadPoolExecutor to handle simulator threads, for now I'm just handling thrown errors, but in the future we might extend, depending on our needs.

Related issue(s):

Fixes #186

Notes for reviewer:

Checklist

• Documented (Code comments, README, etc.)
• Tested (unit, integration, etc.)

[ata-nas]

This is my first review, I will need to do another one for sure. Generally looks good, but I have a couple of questions and a couple of concerns, also a few nit picks.

General comment:
Can you please consider to add javadocs to the tests describing what they aim to achieve? Will make them a lot easier to review and for us to know their purpose in order to validate them?

[mattp-swirldslabs]

Nice work, I like seeing all this new test coverage! I added one suggestion.

[ata-nas]

@georgi-l95 looks good, but the thread pool requires some changes as the current implementation will still silence exceptions.

[ata-nas]

Looks great! Good job @georgi-l95!

[rbarkerSL]

Approval applies to .gitignore

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.62%. Comparing base (2e4d26b) to head (b4d0ef5).
Report is 2 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main     #330      +/-   ##
============================================
+ Coverage     94.05%   94.62%   +0.57%     
- Complexity      300      316      +16     
============================================
  Files            68       69       +1     
  Lines          1177     1228      +51     
  Branches         82       84       +2     
============================================
+ Hits           1107     1162      +55     
+ Misses           57       55       -2     
+ Partials         13       11       -2     

Files with missing lines	Coverage Δ
...a/com/hedera/block/common/utils/Preconditions.java	100.00% <100.00%> (ø)
...edera/block/simulator/BlockStreamSimulatorApp.java	93.75% <100.00%> (+1.44%)	⬆️
...dera/block/simulator/config/data/StreamStatus.java	100.00% <100.00%> (ø)
...ck/simulator/grpc/PublishStreamGrpcClientImpl.java	96.07% <100.00%> (+0.72%)	⬆️
...ra/block/simulator/grpc/PublishStreamObserver.java	100.00% <100.00%> (ø)
.../block/simulator/metrics/SimulatorMetricTypes.java	100.00% <100.00%> (ø)
...dera/block/simulator/mode/CombinedModeHandler.java	100.00% <100.00%> (ø)
...dera/block/simulator/mode/ConsumerModeHandler.java	100.00% <100.00%> (ø)
...era/block/simulator/mode/PublisherModeHandler.java	100.00% <100.00%> (+7.69%)	⬆️

---- 🚨 Try these New Features:

• Flaky Tests Detection - Detect and resolve failed and flaky tests