* chore: bump langchain to v0.0.213 from v0.0.186
* fix: handle abort edge cases:
- abort message server-side if response experienced error mid-generation
- attempt to recover message if aborting resulted in error
- if abortKey is not provided, use conversationId if it exists
- if headers were already sent, send an Event stream message
- issue warning for possible Google censor/filter
refactor(streamResponse): for `sendError`, allow passing overrides so that error can include partial generation, improve typing for `sendMessage`
* chore(MessageContent): remove eslint warning for unused `i`, rephrase unfinished message text
* fix(useSSE): avoid invoking cancelHandler if the abort response was 404
* chore(TMessage): remove unnecessary, unused legacy message property `submitting`
* chore(TMessage): remove unnecessary legacy message property `cancelled`
* chore(abortMiddleware): remove unused `errorText` property to avoid confusion
379e470e38