fix: resolve use-after-free in RawClientImpl config access

[johnlanni]

Fixed a critical use-after-free bug where RawClientImpl would crash when accessing config_.disableOutlierEvents() after the config object was destroyed.

Root Cause:

• RawClientImpl held a const Config& reference without reference counting
• When AsyncClientImpl::initialize() created a new config_ shared_ptr, the old config object was destroyed
• RawClientImpl continued processing async network data and accessed the destroyed config reference, causing a crash

Solution:
Changed RawClientImpl to hold ConfigSharedPtr instead of const Config&, ensuring proper lifetime management through reference counting.

Changes:

• Modified RawClientFactory::create() to accept ConfigSharedPtr
• Updated RawClientImpl to store ConfigSharedPtr instead of reference
• Changed all config_.method() calls to config_->method()
• Updated AsyncClientImpl to pass config_ directly (already shared_ptr)
• Fixed unit tests to use ConfigSharedPtr

Test Plan:

• bazel build //source/exe:envoy-static - PASS
• bazel test //test/extensions/filters/network/common/redis:all - PASS (3/3)
• bazel test //test/extensions/filters/network/common/redis:client_impl_test - PASS

Co-developed-by: Claude noreply@anthropic.com

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Note

Switch RawClient to hold and receive ConfigSharedPtr, updating factory, impl, callers, and tests to avoid lifetime issues.

• Redis client internals:
  • Replace const Config& with ConfigSharedPtr across RawClientFactory::create, RawClientImpl::{create,ctor} and member config_.
  • Update all config access from config_.method() to config_->method().
• Async client:
  • Pass shared config_ directly to client_factory_.create(...) in AsyncClientImpl::threadLocalActiveClient.
• Tests:
  • Update Redis raw client tests and factory tests to construct and pass ConfigSharedPtr and match new interfaces.

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