import/ export schema mapping models and generate schema mapping suggestions

# 🙋 feature request

use pre-trained models for schema mapping are getting more and more popular in SDTM use cases.

## 🤔 Expected Behavior

support import/ export SMR model
support generate mapping suggestions

## 😯 Current Behavior
call internal API end point and need to use recipe_id

## 💁 Possible Solution

## 🔦 Context

## 💻 Examples

Start by reviewing the existing internal API endpoint and how recipe_id is currently used. Define the expected import and export behavior for SMR models and how mapping suggestions should be generated, then identify the relevant client entry points and tests. Done means both model exchange and suggestion generation are supported through the client.

Written by the indexing model from the issue text.