nes: show thumbsdown icon for previously rejected NES in log tree

[ulugbekna]

Previously rejected NES entries now show a 👎 icon instead of no specific icon. Uses direct outcome assignment to avoid false warnings on the succeeded→previouslyRejected transition. Also registers the rebasedEdit (when present) with the rejection collector.

[Copilot]

Pull request overview

Updates the Copilot inline edits (NES) logging UI to clearly indicate when a suggestion was previously rejected, by introducing a dedicated log outcome and icon and wiring it up from the provider logic.

Changes:

• Added a thumbs-down icon and mapped a new previouslyRejected log outcome to it.
• Introduced markAsPreviouslyRejected() on InlineEditRequestLogContext to set the new outcome without triggering outcome-transition warnings.
• Updated NextEditProvider to mark log contexts as previously rejected and to reject rebasedEdit when present.

Show a summary per file

File	Description
extensions/copilot/src/platform/inlineEdits/common/utils/utils.ts	Adds a new thumbs-down icon definition for log rendering.
extensions/copilot/src/platform/inlineEdits/common/inlineEditLogContext.ts	Adds previouslyRejected outcome, icon mapping, and a setter method to apply it.
extensions/copilot/src/extension/inlineEdits/node/nextEditProvider.ts	Marks relevant flows as previously rejected and ensures rebased edits are collected for rejection.

Copilot's findings

Comments suppressed due to low confidence (1)

extensions/copilot/src/extension/inlineEdits/node/nextEditProvider.ts:340

• New behavior is introduced for the “previously rejected” paths (setting a distinct log outcome and rejecting rebasedEdit when present), but there doesn’t appear to be test coverage validating it. Please add/extend NextEditProvider tests to cover: (1) a cached edit marked rejected results in the log context being marked previously rejected, and (2) when a cached rejected edit has rebasedEdit, that exact edit is passed to RejectionCollector.reject.

		const cachedEdit = this._nextEditCache.lookupNextEdit(docId, documentAtInvocationTime, selections);
		if (cachedEdit?.rejected) {
			logger.trace('cached edit was previously rejected');
			telemetryBuilder.setStatus('previouslyRejectedCache');
			telemetryBuilder.setWasPreviouslyRejected();
			logContext.markAsPreviouslyRejected();
			const rejectedEdit = cachedEdit.rebasedEdit ?? cachedEdit.edit;
			if (rejectedEdit) {
				this._rejectionCollector.reject(docId, rejectedEdit);
			}

• Files reviewed: 3/3 changed files
• Comments generated: 2