feat: update inject details

### Additions

* added new type `TInjectType`
* added new type `IInjectType`
* added new interface `ChannelInterface`
* added new type `TChannelType`
* added new type `IChannelType`
* added new enum `InjectTypes`
* added field `inject: TInjectType!` to `TInjectDetailsType`

### Changes

* field `DefinitionType.injects: [DefinitionInjectType!]!` changed to `DefinitionType.injects: [IInjectType!]!`
* field `DefinitionType.channels: [!]!` changed to `DefinitionType.injects: [IInjectType!]!`
* field `ActionLogInterface.channel: DefinitionChannelType!` changed to `ActionLogInterface.channel: ChannelInterface!`
* query `channel(channelId: ID!): DefinitionChannelType!` changed to `channel(channelId: ID!): ChannelInterface!)`
* query `exerciseChannels(exerciseId: ID!): [DefinitionChannelType!]!` changed to `exerciseChannels(exerciseId: ID!): [ChannelInterface!]!`
* field `IInjectDetailsType.inject: DefinitionInjectType!` changed to `IInjectDetailsType.inject: IInjectType!`

### Deletions

* removed field `user: RestrictedUser` from all `Email` objects, use `ActionLogInterface.user` instead
* removed type `DefinitionInjectType`
* removed type `DefinitionChannelType`

Closes #463