feat: Add AI tool building capabilities (#7336)

Github issue / Community forum post (link here to close automatically):
https://community.n8n.io/t/langchain-memory-chat/23733

---------

Signed-off-by: Oleg Ivaniv <me@olegivaniv.com>
Co-authored-by: Oleg Ivaniv <me@olegivaniv.com>
Co-authored-by: Val <68596159+valya@users.noreply.github.com>
Co-authored-by: Alex Grozav <alex@grozav.com>
Co-authored-by: कारतोफ्फेलस्क्रिप्ट™ <aditya@netroy.in>
Co-authored-by: Deborah <deborah@starfallprojects.co.uk>
Co-authored-by: Jesper Bylund <mail@jesperbylund.com>
Co-authored-by: Jon <jonathan.bennetts@gmail.com>
Co-authored-by: Michael Kret <88898367+michael-radency@users.noreply.github.com>
Co-authored-by: Giulio Andreini <andreini@netseven.it>
Co-authored-by: Mason Geloso <Mason.geloso@gmail.com>
Co-authored-by: Mason Geloso <hone@Masons-Mac-mini.local>
Co-authored-by: Mutasem Aldmour <mutasem@n8n.io>

packages/@n8n/nodes-langchain/nodes/chains/ChainSummarization/prompt.ts

@@ -0,0 +1,20 @@
+export const REFINE_PROMPT_TEMPLATE = `Your job is to produce a final summary
+We have provided an existing summary up to a certain point: "{existing_answer}"
+We have the opportunity to refine the existing summary
+(only if needed) with some more context below.
+------------
+"{text}"
+------------
+
+Given the new context, refine the original summary
+If the context isn't useful, return the original summary.
+
+REFINED SUMMARY:`;
+
+export const DEFAULT_PROMPT_TEMPLATE = `Write a concise summary of the following:
+
+
+"{text}"
+
+
+CONCISE SUMMARY:`;