fix: adds order by timestamp

[wolf4ood]

What this PR changes/adds

Adds a deterministic order by stateTimestamp field in nextNotLeased method of state machines:

• PolicyMonitor
• DataPlane
• ContractNegotiation
• TransferProcess

This will allow a consistent and fair processing order for entities based on their state.
By using an index on state + timestamp it will also speedup processing states that need to transition and it will also lower down the usage of the database which we constantly poll for next states to process. State machine should not poll final state or states that needs to be monitored for a long period of time.

While profiling state machine the PolicyMonitor was on of those which spikes the CPU usage of both connector and
database since basically it's constantly polling the database for the entries in STARTED state, which grows over time without transitioning. Also the edc.policy.monitor.state-machine.iteration-wait-millis didn't help since the state machine does not wait if at least one entry has been process in a tick. To lower down the load to the database usage of the PolicyMonitor state machine the processMonitoring processor now return false if no state transition is made. In this way the wait configuration can be applied.

Why it does that

Briefly state why the change was necessary.

Further notes

We might think of reworking PolicyMonitor state machine, since it's a bit different from the other state machine and it needs constantly checking on transfer process states and policy evaluation. In the current form can be a CPU hog

Linked Issue(s)

Closes #4308

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Codecov Report

Attention: Patch coverage is 81.13208% with 10 lines in your changes missing coverage. Please review.

Project coverage is 75.18%. Comparing base (7f20ba5) to head (9957c93).
Report is 331 commits behind head on main.

Files	Patch %	Lines
...negotiation/store/SqlContractNegotiationStore.java	81.48%	4 Missing and 1 partial ⚠️
...transferprocess/store/SqlTransferProcessStore.java	73.68%	4 Missing and 1 partial ⚠️

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Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4316      +/-   ##
==========================================
+ Coverage   71.74%   75.18%   +3.43%     
==========================================
  Files         919     1052     +133     
  Lines       18457    21114    +2657     
  Branches     1037     1180     +143     
==========================================
+ Hits        13242    15874    +2632     
+ Misses       4756     4725      -31     
- Partials      459      515      +56     

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[ndr-brt]

I also agree that the PolicyMonitor could be refactored into a watchdog, when it was implemented the state machine looked like the more natural thing to do, but in fact there's only one non final state (STARTED) so the SM is definitely overkill