Aliases - load temp aliases, when aliases are missing

[ShaneBeee]

Description

This PR aims to create temporary aliases for missing materials. This will help future proof Skript during future Minecraft releases.
A small example was the release of Minecraft 1.16. When Spigot was released, we had to try to rush a release on Skript to have aliases available to users. The main problem here was these aliases were added to Skript 2.5-alpha versions.
Users who wish to stay on a stable release (ie: 2.4.1 at the time) would not have access to these new aliases.
With this change, and the introduction to BlockData recently, Skript users will not have to wait for a Skript update to use the new aliases.
This gives us more time to write/test new aliases for Skript, without having to worry about pushing out an update right away.

Notes:

• I included ¦s as a temporary plural variant of each alias. Clearly this will NOT be perfect with some items which have a different plural spelling, but at least it helps with the main ones until we have time to write out the correct aliases for a release.
• In the Aliases#loadMissingAliases() method, Im checking for the existence of Material#getKey(). This is due to the fact that these temp aliases will only ever be needed for future versions of Minecraft.
• The debug message I made yellow, to stand out when we DO write aliases in the future and need to find out which ones are missing if we just so happen to miss one.

Example:

I removed a couple aliases to test, here is an example of how it would look in console during debug when an alias is missing:

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Target Minecraft Versions: the future
Requirements: none
Related Issues: none