updated email template manager, added reset_email_by_code to multiple places

[tusharpandey13]

This PR adds some minor changes to already existing methods:

• support for reset_email_by_code for email template methods
• support for 'custom' as email provider
• Updated PATCH response type for ACUL methods.

Changed endpoint methods:

Path	Method	Alias
/prompts/{prompt}/screen/{screen}/rendering	GET	getRendering
/prompts/{prompt}/screen/{screen}/rendering	PATCH	updateRendering
/connections	POST	create
/email-templates	POST	create
/email-templates/{templateName}	GET	get
/email-templates/{templateName}	PATCH	update
/email-templates/{templateName}	PUT	put