Remove simpleauth

Simple Auth used to provide auth over HTTP. The original motivation
behind this was this was a simple way to add Cloudron Auth integration.
Back in the day, Cloudron Auth was a requirement for apps but this is
not the case anymore.

This is currently not used by any app and having this might encourage
people to make Cloudron specific un-upstreamable changes.

docs/references/addons.md

@@ -318,67 +318,3 @@ cloudron exec
 > swaks --server "${MAIL_SMTP_SERVER}" -p "${MAIL_SMTP_PORT}" --from "${MAIL_SMTP_USERNAME}@${MAIL_DOMAIN}" --body "Test mail from cloudron app at $(hostname -f)" --auth-user "${MAIL_SMTP_USERNAME}" --auth-password "${MAIL_SMTP_PASSWORD}"
 ```
 
-## simpleauth
-
-Simple Auth can be used for authenticating users with a HTTP request. This method of authentication is targeted
-at applications, which for whatever reason can't use the ldap addon.
-The response contains an `accessToken` which can then be used to access the [Cloudron API](/references/api.html).
-
-Exported environment variables:
-```
-SIMPLE_AUTH_SERVER=    # the simple auth HTTP server
-SIMPLE_AUTH_PORT=      # the simple auth server port
-SIMPLE_AUTH_URL=       # the simple auth server URL. same as "http://SIMPLE_AUTH_SERVER:SIMPLE_AUTH_PORT
-SIMPLE_AUTH_CLIENT_ID  # a client id for identifying the request originator with the auth server
-```
-
-This addons provides two REST APIs:
-
-**POST /api/v1/login**
-
-Request JSON body:
-```
-{
-  "username": "<username> or <email>",
-  "password": "<password>"
-}
-```
-
-Response 200 with JSON body:
-```
-{
-  "accessToken": "<accessToken>",
-  "user": {
-    "id": "<userId>",
-    "username": "<username>",
-    "email": "<email>",
-    "admin": <admin boolean>,
-    "displayName": "<display name>"
-  }
-}
-```
-
-**GET /api/v1/logout**
-
-Request params:
-```
-?access_token=<accessToken>
-```
-
-Response 200 with JSON body:
-```
-{}
-```
-
-For debugging, [cloudron exec](https://www.npmjs.com/package/cloudron) can be used to run the `curl` tool within the context of the app:
-```
-cloudron exec
-
-> USERNAME=<enter username>
-
-> PASSWORD=<enter password>
-
-> PAYLOAD="{\"clientId\":\"${SIMPLE_AUTH_CLIENT_ID}\", \"username\":\"${USERNAME}\", \"password\":\"${PASSWORD}\"}"
-
-> curl -H "Content-Type: application/json" -X POST -d "${PAYLOAD}" "${SIMPLE_AUTH_ORIGIN}/api/v1/login"
-```