LDEV-6243, LDEV-6244, LDEV-6245: fix race condition, perf improvements

[zspitzer]

Summary

Three tickets, 9 commits. Bug fix + performance improvements found via JFR profiling.

LDEV-6243 — member function race condition

CommonUtil.getMembers() publish-before-populate race causes intermittent Can't cast Object type [Struct] to a value of type [image] on member function calls under concurrency (~1% failure rate).

Fix: Double-checked locking with volatile, build into local before publish.

LDEV-6244 — replace GetApplicationSettings BIF

getCoders() called GetApplicationSettings BIF via reflection on every image operation, triggering 128k DummyWSHandler exceptions per benchmark run.

Fix: Use pc.getApplicationContext().getCustom("image") directly, same pattern as extension-s3. Also fixes the missing o = assignment for the "coders" fallback key.

LDEV-6245 — performance (5 fixes)

• Remove redundant _coder static cache (if (true || bypass)
• Fix missing return in AImageIOInterface.write() — was writing files twice
• Stop throwing exceptions for format matching — invert delegation in getFormatbyMimeType
• Resolve MIME type (Tika) once per operation and pass to coders via new FormatExtract overload
• Add misnamed file tests (JPEG as .png, PNG as .jpg, WebP as .jpg, etc.)

Benchmark results (5k ops, inspect never)

Test	Before	After	Change
image-read	872/s	1,230/s	+41%
image-convert	272/s	453/s	+67%
image-info	801/s	1,093/s	+36%
image-write	306/s	333/s	+9%
image-resize	250/s	270/s	+8%

Exceptions: 354,332 → 2,309 (-99.3%)

Test plan

• All existing image tests pass (testLabels=image, Failures: 0)
• New misnamed file tests pass (8 tests — JPEG/PNG/WebP with wrong extensions)
• Member function race verified: 0 failures post-fix (was 23/2002)
• Benchmarked with JFR before and after