feat: Add Chat Trigger node (#7409)

Signed-off-by: Oleg Ivaniv <me@olegivaniv.com>
Co-authored-by: Jan Oberhauser <jan.oberhauser@gmail.com>
Co-authored-by: Jesper Bylund <mail@jesperbylund.com>
Co-authored-by: OlegIvaniv <me@olegivaniv.com>
Co-authored-by: Deborah <deborah@starfallprojects.co.uk>
Co-authored-by: Jan Oberhauser <janober@users.noreply.github.com>
Co-authored-by: Jon <jonathan.bennetts@gmail.com>
Co-authored-by: कारतोफ्फेलस्क्रिप्ट™ <aditya@netroy.in>
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/editor-ui/src/n8n-theme.scss

@@ -1,3 +1,4 @@
+@import '@n8n/chat/css';
 @import 'styles/plugins';
 
 :root {
@@ -170,6 +171,8 @@
 		var(--node-type-background-l)
 	);
 	--node-error-output-color: #991818;
+
+	--chat--spacing: var(--spacing-s);
 }
 
 .clickable {