Add basic item matching support

[me4502]

So few problems atm:

• UX maybe a bit meh when setting from ingame, may require a way to get/set the stringified thing directly to fix/filter it more.
• List tags are a bit jank. It appears this is how it's handled in MC at least, lists of compound tags are unordered, and lists of other tags are ordered. All ordered compound lists are lists of lists with a single compound tag as a child.
• For Tools 2.0, using a BaseItem with a matcher means we can no longer use a Map for tool lookups, so we'd need some way around this
• This would ideally be extended to BaseBlock and BaseEntity too, so we'd need to see how that works

Definitely open to suggestions

This was done as it's the most flexible way of handling NBT data and is also usable in CraftBook (and maybe WG if blacklist is extended for item nbt or whatever)

[codecov]

Codecov Report

Merging #1685 (1a83f42) into master (913d4d6) will decrease coverage by 0.01%.
The diff coverage is 0.00%.

@@             Coverage Diff              @@
##             master    #1685      +/-   ##
============================================
- Coverage     11.44%   11.43%   -0.02%     
  Complexity     1002     1002              
============================================
  Files           805      805              
  Lines         32598    32646      +48     
  Branches       3783     3800      +17     
============================================
  Hits           3732     3732              
- Misses        28688    28736      +48     
  Partials        178      178              

Impacted Files	Coverage Δ	Complexity Δ
...main/java/com/sk89q/worldedit/blocks/BaseItem.java	0.00% <0.00%> (ø)	0.00 <0.00> (ø)
...in/java/com/sk89q/worldedit/util/nbt/NbtUtils.java	0.00% <0.00%> (ø)	0.00 <0.00> (ø)

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