[BUG] Extensions handshake is failing with TLS after change to utilize lookupInitializedExtensionById

[cwperks]

What is the bug?

Handshake with an extension fails with TLS because the extension is not initialized at the time of first handshake. There was a recent change in core to change the access modifiers of many methods within ExtensionsManager and direct access to the extensionIdMap was removed. In order to fix compilation on the security plugin, there was a change in the SecurityRequestHandler to use the public method lookupInitializedExtensionById, but this data structure only contains initialized extensions.

One way of solving this issue is to have the extension settings exposed to the security plugin so the security plugin can lookup in a map of extension settings to see if a unique id is present.

[peternied]

Looks like we need an lookupUninitializedExtensionById or something similar to handle this scenario in core

[cwperks]

I included a method to get extension settings in this PR: opensearch-project/OpenSearch#6870

[cwperks]

@peternied I opened a PR in core and a PR here for a fix:

• Adds ExtensionsManager.lookupExtensionSettingsById OpenSearch#7466
• Use ExtensionsManager.lookupExtensionSettingsById when verifying extension unique id #2749