[GH-852] Configurator: Migrate effects config

[agustinesco]

Motivation

Keep migrating fields from config.json to configurator app

Part of #852

Summary of changes

• Added embedded schema Effect to be shared across distinct structs
• Adapted in game effects to work with a field instead of looking for effects in the game config
• Added show and edit of effects to configurator app

How to test it?

Start a match and everything should keep working as before

Checklist

• Tested the changes locally.
• Reviewed the changes on GitHub, line by line.
• This change requires new documentation.
  • Documentation has been added/updated.

[tvillegas98]

LGTM

[AminArria]

Not sure where/how, but the Valtimer dash is broken

Stacktrace

[error] GenServer #PID<0.1554.0> terminating
** (KeyError) key :execute_multiple_times not found in: {:damage_immunity, %{effect_delay_ms: 0, execute_multiple_times: false}}

If you are using the dot syntax, such as map.field, make sure the left-hand side of the dot is a map
    (arena 0.7.1) lib/arena/game/effect.ex:158: anonymous fn/5 in Arena.Game.Effect.apply_effect_mechanic/3
    (stdlib 5.0.2) maps.erl:416: :maps.fold_1/4
    (elixir 1.16.1) lib/enum.ex:2528: Enum."-reduce/3-lists^foldl/2-0-"/3
    (arena 0.7.1) lib/arena/game/effect.ex:143: anonymous fn/2 in Arena.Game.Effect.apply_effect_mechanic_to_entities/1
    (stdlib 5.0.2) maps.erl:416: :maps.fold_1/4
    (arena 0.7.1) lib/arena/game_updater.ex:259: Arena.GameUpdater.handle_info/2
    (stdlib 5.0.2) gen_server.erl:1077: :gen_server.try_handle_info/3
    (stdlib 5.0.2) gen_server.erl:1165: :gen_server.handle_msg/6
    (stdlib 5.0.2) proc_lib.erl:241: :proc_lib.init_p_do_apply/3