Add Wrapped POLYX example contract

[codecov[bot]]

Codecov Report

Merging #1392 (16d1446) into develop (1b6ea87) will increase coverage by 0.00%. The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop    #1392   +/-   ##
========================================
  Coverage    43.37%   43.38%           
========================================
  Files          141      141           
  Lines        30387    30387           
========================================
+ Hits         13181    13184    +3     
+ Misses       17206    17203    -3     

Impacted Files	Coverage Δ
pallets/settlement/src/lib.rs	44.70% <0.00%> (+0.07%)	:arrow_up:
pallets/balances/src/lib.rs	57.23% <0.00%> (+0.13%)	:arrow_up:
primitives/src/asset_identifier.rs	98.34% <0.00%> (+0.41%)	:arrow_up: