perf(approvers): Reduce approver's pipeline allocations

[rabbitstack]

What is the purpose of this PR / why it is needed?

The approver path is allocation-heavy because we have to clone the CreateFile event so it can outlive the ETW callback. To alleviate the pressure on the heap allocator, we aggressively pool the event records, their data buffers, and the callstack return
addresses.

List of optimizations:

• event record, data buffer, and callstack pooling
• registry and file path interning to avoid repetitive UTF16 string decoding
• wildcard matching with a case-insensitive variant to eliminate strings.ToLower from the hot path

What type of change does this PR introduce?

---

Uncomment one or more /kind <> lines:

/kind feature (non-breaking change which adds functionality)

/kind bug-fix (non-breaking change which fixes an issue)

/kind refactor (non-breaking change that restructures the code, while not changing the original functionality)

/kind breaking (fix or feature that would cause existing functionality to not work as expected

/kind cleanup

/kind improvement

/kind design

/kind documentation

/kind other (change that doesn't pertain to any of the above categories)

Any specific area of the project related to this PR?

---

Uncomment one or more /area <> lines:

/area instrumentation

/area telemetry

/area rule-engine

/area filters

/area yara

/area event

/area captures

/area alertsenders

/area outputs

/area rules

/area filaments

/area config

/area cli

/area tests

/area ci

/area build

/area docs

/area deps

/area evasion

/area other

Special notes for the reviewer

---

Does this PR introduce a user-facing change?

---