Implement client behaviour packs

[DasEtwas]

Overview

• This PR enables the downloading of behavior packs.
• It adds a new directory client_behavior_packs in the data folder.
• Resource Packs belong in resource_packs as before, and Behavior Packs belong in client_behavior_packs
• The server now checks if a pack is of the right type for the folder it is in by checking metadata.json:modules[n].type
• For setting the scripting flag in the resource data info packet, the server now reads the zip's entry list and sets this flag to true is a file ending with .js was found

Motivation

• Client-side behavior packs for normal minecraft worlds can now be used
• By enabling the use of client-side behavior packs, plugin developers can now enhance their plugins using ScriptCustomEventPacket etc. to trigger client-side JavaScript (on Win10, where scripts are supported).

Testing

This PR was tested to work in the following cases (meaning players could join and download and display the packs):

• One resource pack loaded
• One behavior pack loaded
• One resource pack and behavior pack loaded
  (tested on android and win)

furthermore:

• requiresScripts() was tested to work by placing a .js file in a behavior pack

Problems

• The newly added errors don't seem to print correctly, they print the translation keys instead, at least in my build. Submodules were cloned.

New language keys

nukkit.resources.unsupported-module-type
nukkit.resources.invalid-type-resource
nukkit.resources.invalid-type-behavior
nukkit.resources.loaded-resource-pack
nukkit.resources.loaded-behavior-pack

Further ideas

It may make sense to check if a client supports scripting, and if not, set scripting to false in the resource info packet.

[DasEtwas]

Please excuse @belohnung 's commits, they don't seem to affect my diff.

[PetteriM1]

Do you have an example behavior pack this can be tested with? Also maybe it could be a good idea to bump the API version.

[DasEtwas]

Not one to post here.

[ghost]

Behaviour packs is applies by client? I can create behaviour pack with changed stack size of, e.x. golden apple and it can be work?

[belohnung]

Behaviour packs is applies by client? I can create behaviour pack with changed stack size of, e.x. golden apple and it can be work?

This only supports client features and doesn't affect server logic.

[snaildos]

Is this still maintained or going to be tested?