Remove signup fragment and stages mode arguments

app/proguard-rules.pro

...a/org/futo/circles/auth/feature/sign_up/SignUpFragment.kt

.../org/futo/circles/auth/feature/sign_up/SignUpViewModel.kt

...circles/auth/feature/sign_up/password/PasswordFragment.kt

...o/circles/auth/feature/uia/flow/SignUpStagesDataSource.kt

.../main/java/org/futo/circles/auth/model/PasswordModeArg.kt

...src/main/java/org/futo/circles/auth/model/TermsModeArg.kt

auth/src/main/res/layout/fragment_sign_up.xml

auth/src/main/res/navigation/nav_graph_auth.xml

auth/src/main/res/values/strings.xml