chore: remove contracts & asset related pallets

[al3mart]

Removes anything contracts and assets from mainnet runtime.
Updates para_id for mainnet.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 5 lines in your changes missing coverage. Please review.

Project coverage is 7.44%. Comparing base (7f7166b) to head (369ad75).

Files	Patch %	Lines
runtime/mainnet/src/config/proxy.rs	0.00%	4 Missing ⚠️
node/src/chain_spec.rs	0.00%	1 Missing ⚠️

@@                   Coverage Diff                    @@
##           peter/mainnet-runtime    #241      +/-   ##
========================================================
+ Coverage                   7.43%   7.44%   +0.01%     
========================================================
  Files                         35      34       -1     
  Lines                       2584    2457     -127     
  Branches                    2584    2457     -127     
========================================================
- Hits                         192     183       -9     
+ Misses                      2392    2274     -118     

Files	Coverage Δ
runtime/mainnet/src/lib.rs	5.47% <ø> (+1.57%)	⬆️
node/src/chain_spec.rs	0.00% <0.00%> (ø)
runtime/mainnet/src/config/proxy.rs	0.00% <0.00%> (ø)