GHSA-g274-c6jj-h78p: PocketMine-MP allows malicious client data to waste server resources due to lack of limits for explode()

Due to lack of limits by default in the explode() function, malicious clients were able to abuse some packets to waste server CPU and memory.

This is similar to a previous security issue published in https://github.com/pmmp/PocketMine-MP/security/advisories/GHSA-gj94-v4p9-w672, but with a wider impact, including but not limited to:

• Sign editing
• LoginPacket JWT parsing
• Command parsing

However, the estimated impact of these issues is low, due to other limits such as the packet decompression limit.