chore: Refactors to prepare for adding the block node service client

[timfn-hg]

Description:
This is part one of adding the block node service client to retrieve server status information from. The primary changes are moving some of the to-be common components out of BlockNodeConnection and into a new shared class: AbstractBlockNodeConnection. Eventually the existing BlockNodeConnection will be changed to BlockNodeStreamingConnection and a new BlockNodeServiceConnection will be created for the service client.

Related issue(s):

Fixes #21856

Notes for reviewer:

Checklist

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

[lfdt-bot]

✅ Snyk checks have passed. No issues have been found so far.

Status	Scanner	Critical	High	Medium	Low	Total (0)
✅	Open Source Security	0	0	0	0	0 issues

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[codacy-production]

Coverage summary from Codacy

See diff coverage on Codacy

Coverage variation	Diff coverage
✅ +0.00% (target: -1.00%)	✅ 92.98%

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (dd12bcc)	105808	79241	74.89%
Head commit (597ba0c)	105833 (+25)	79261 (+20)	74.89% (+0.00%)

Coverage variation is the difference between the coverage for the head and common ancestor commits of the pull request branch: <coverage of head commit> - <coverage of common ancestor commit>

Diff coverage details

	Coverable lines	Covered lines	Diff coverage
Pull request (#22354)	171	159	92.98%

Diff coverage is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: <covered lines added or modified>/<coverable lines added or modified> * 100%

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[codecov]

Codecov Report

❌ Patch coverage is 89.47368% with 18 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...ks/impl/streaming/AbstractBlockNodeConnection.java	80.76%	9 Missing and 1 partial ⚠️
...app/blocks/impl/streaming/BlockNodeConnection.java	94.52%	0 Missing and 4 partials ⚠️
...cks/impl/streaming/BlockNodeConnectionManager.java	78.57%	2 Missing and 1 partial ⚠️
.../blocks/impl/streaming/BlockNodeClientFactory.java	94.73%	1 Missing ⚠️

@@            Coverage Diff            @@
##               main   #22354   +/-   ##
=========================================
  Coverage     71.00%   71.00%           
- Complexity    24808    24822   +14     
=========================================
  Files          2718     2720    +2     
  Lines        105905   105930   +25     
  Branches      11171    11175    +4     
=========================================
+ Hits          75201    75219   +18     
- Misses        26618    26623    +5     
- Partials       4086     4088    +2     

Files with missing lines	Coverage Δ	Complexity Δ
...ode/app/blocks/impl/streaming/ConnectionState.java	100.00% <100.00%> (ø)	5.00 <5.00> (?)
.../blocks/impl/streaming/BlockNodeClientFactory.java	95.00% <94.73%> (-5.00%)	3.00 <2.00> (+1.00)	⬇️
...cks/impl/streaming/BlockNodeConnectionManager.java	90.02% <78.57%> (ø)	69.00 <1.00> (ø)
...app/blocks/impl/streaming/BlockNodeConnection.java	88.62% <94.52%> (-0.24%)	80.00 <15.00> (-8.00)
...ks/impl/streaming/AbstractBlockNodeConnection.java	80.76% <80.76%> (ø)	17.00 <17.00> (?)

... and 1 file with indirect coverage changes

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[timfn-hg]

XTS: https://github.com/hiero-ledger/hiero-consensus-node/actions/runs/19899781327