Incompatibilities between s2-ws-json specifications and datamodel-codegen

[lfse-slafleur]

As found here: #39 currently there are dots in the message names and string constants are defined as enums. These discussion in s2-ws-json may be found here:

• openapi message_type is defined as an enum instead of a const s2-json#17
• openapi dots are used in schema names s2-json#18

We need to wait until these discussions are done and we know how to proceed for this project. In the mean time, we are altering the openapi.yml manually by replacing dots in the name by underscores and by changes the message_type enum to constants (examples are in the s2-ws-json discussions).