HDDS-13774. [Recon] Consolidate NSSummary endpoint tests into one suite

[priyeshkaratha]

What changes were proposed in this pull request?

The NSSummary REST API had three near-duplicate test classes TestNSSummaryEndpointWith{FSO,Legacy,OBSAndLegacy} (~4,500 lines). This replaces them with a single @ParameterizedClass suite (TestNSSummaryEndpoint) driven by per-layout scenario objects, sharing all constants, fixtures, and assertions.

• Duplication: FSO and Legacy were ~95% identical; all three repeated the mock SCM, replica generation, and populate logic.
• Weak replication coverage: the three Ratis tests asserted getReplicatedSize(response.getSize()) == response.getSizeWithReplica() — both sides from the endpoint's own output, so they passed regardless of correctness. Keys were written with factor ONE, so sizeWithReplica collapsed to the raw size despite elaborate multi-block/container setup.

Multi-block keys now use genuine RATIS/THREE replication; replication tests assert sizeWithReplica (3×) and raw size against independent constants.

What is the link to the Apache JIRA

HDDS-13774

How was this patch tested?

TestNSSummaryEndpoint: 117 run, 0 failures. checkstyle.sh and rat.sh clean

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