Implement prepare_request/build_request and the corresponding Session.send()

[alive4ever]

Is your feature request related to a problem? Please describe.

Currently, the requests api of curl_cffi is missing prepare_request or httpx's build_request method. The method is useful to construct request object and ability to view or edit the request object before sending the request via Session().send or Client().send().

Describe the solution you'd like

httpx's build_request or requests' prepare_request method implemented in the requests api of curl_cffi

Describe alternatives you've considered

Using curl_cffi as requests adapter, so expected requests features are available.

Context

An example of the usefulness of build_request method in action.

client = requests.Session()
# build_request is httpx method, similar to prepare_request
req = client.build_request(method: 'GET', url, headers, cookies, data)
# show request headers
req.headers
# Update user-agent header
req.headers['User-Agent'] = 'my_web_crawler/0.1'
# show request payload
req.content
# Update request payload using json string
data =  { 'hello': 'world'}
req.content = bytes(json.dumps(data), 'utf-8')
# Update request method
req.method = 'POST'
# send the built request after fixing the issue
resp = client.send(req)

[lexiforest]

Good suggestion. On our TODO list now.