feat(api): get /api/user for public user details

feat(schema, shared, api): move all types to shared, separate schema
 * schema is now stored in a separate crate to avoid dependency cycles
 * added note in README.md about handling unwraps

feat(api): reimpl all_games and my_games

fix(api): use gamestate consts

feat(api): stubs for most game endpoints, complete create

feat(client): init game handlers module

feat(api): impl models action, gamedata, game

feat(api): create session on register

feat(api): increase session lifetime to 30 days

feat(api): logout endpoint

feat(api): session validation

feat(api): login password verification

WIP(api): session management

fix(api): /ping -> /api/ping

feat(api): init redis session backend

fix(api): check if user exists before hashing password on registration

feat(api): reimpl user registration

fix(api): skip user model password field

fix(api): NewUser -> InsertableUser

feat(api): user model