Go to Implementation fix for not finding type-annotated implementation

[navya9singh]

The addImplementationReferences function had an inverted condition that prevented it from finding implementations assigned via type annotations (e.g., object literals, return statements, type assertions).

The condition !state.seenContainingTypeReferences.AddIfAbsent(typeHavingNode) was incorrect — AddIfAbsent returns true when the node is newly added (first seen), so the ! caused the block to only execute for duplicates and skip first encounters entirely.

Removed the negation to match Strada's state.markSeenContainingTypeReference(typeHavingNode) semantics. Found this issue due to a bug filed in VS https://dev.azure.com/devdiv/DevDiv/_workitems/edit/3011057

[Copilot]

Pull request overview

Fixes a logic error in the language-service “implementations” reference collection that prevented discovering implementations introduced via type annotations (notably object literals assigned to interface-typed variables), and updates fourslash coverage/baselines accordingly.

Changes:

• Correct addImplementationReferences to process a containing type-reference node on first encounter (fixing an inverted AddIfAbsent check).
• Add a new fourslash test covering go-to-implementation for an interface-typed object literal assignment.
• Update fourslash baselines to reflect newly discovered implementations (including CodeLens counts).

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
internal/ls/findallreferences.go	Fixes the seen-tracking condition so type-annotated implementation expressions are actually examined and reported.
internal/fourslash/tests/goToImplementationInterfaceObjectLiteral_test.go	Adds a regression fourslash test for go-to-implementation from an interface type annotation to an object literal implementation.
testdata/baselines/reference/fourslash/goToImplementation/goToImplementationInterfaceObjectLiteral.baseline.jsonc	New baseline for the added go-to-implementation fourslash test.
testdata/baselines/reference/fourslash/codeLenses/codeLensInterface01.baseline.jsonc	Updates CodeLens baselines to include the additional implementation found via object-literal type annotation.