Unify metric names and update comments

[citizen-stig]

Description

One of the first steps to enable agentic assisted incidents or performance investigation.

This PR cleans up and documents the SDK’s Influx/Telegraf metrics layer.

• Replaces MetricsTracker::submit_inline with dedicated Metric implementations for blob-sender and sequencer metrics. This makes metric serialization explicit, typed, easier to review, and less dependent on ad hoc line-protocol strings.
• Moves blob-sender metric serialization into sov-blob-sender/src/metrics.rs, including typed metrics for in-flight blob counts, blob snapshots, and scope markers. The scope markers now emit marker=1i instead of the old placeholder foo=1, so dashboards need to be updated accordingly.
• Changes sov_rollup_zkvm and sov_rollup_gas_constant metadata from Influx tags to string fields. This avoids high-cardinality tag explosions from values like hashes, heights, and transaction IDs while preserving useful filterable metadata.
• Adds shared escaping helpers for Influx string field values, so JSON/string metadata is serialized safely and consistently instead of relying on local replace chains.
• Renames several DB/NOMT metrics to use the sov_ prefix, making metric names consistent with the rest of the rollup metrics namespace.
• Adds/updates documentation and changelog entries, including a metrics inventory and explicit migration notes for renamed metrics and changed marker fields.
• Updates tests around gas-constant metrics to assert the new field-based metadata format and to parse only the received UDP payload bytes.

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• I have updated CHANGELOG.md with a new entry if my PR makes any breaking changes or fixes a bug. If my PR removes a feature or changes its behavior, I provide help for users on how to migrate to the new behavior.
• I have carefully reviewed all my Cargo.toml changes before opening the PRs. (Are all new dependencies necessary? Is any module dependency leaked into the full-node (hint: it shouldn't)?)

Linked Issues

• Fixes Metrics: review and check dashboards #2196

Testing

Existing tests are pasing

Docs

Updated metrics description