refactor(chain): make config optional for init phase

[lumtis]

Allow launching a chain with Ignite Network without a config.yml

This doesn't fix #3166

However:

We can't really fix the initial issue about config with no validator without changing the genesis validation logic. When config.yml exists, network commands will read it because it may contain instruction for the build process like the main entrypoint if several main exists.
The solution is to tolerate no validator for a config.yml, and could eventually make sense to consider because the fact that a config can contain information for building process mean that the minimal set content of a config can be used solely for this and so can contain no validator, which is used for experimenting the chain

The second issue --no-check that fails if the config is not valid, is because even if we don't interact with the chain locally when --no-check is provided, we still initialize a chain object that needs read the config to be initialized. The solution is to refactor the chain object in networkchain (separating the chain as information about source about the chain as a local source code)

Creating separate issues for the above so #3166 can be closed

[codecov]

Codecov Report

Merging #3183 (6783acc) into main (a645f1e) will decrease coverage by 0.00%.
The diff coverage is 0.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3183      +/-   ##
==========================================
- Coverage   19.91%   19.91%   -0.01%     
==========================================
  Files         385      385              
  Lines       30460    30463       +3     
==========================================
  Hits         6066     6066              
- Misses      23810    23813       +3     
  Partials      584      584              

Impacted Files	Coverage Δ
ignite/cmd/chain_init.go	0.00% <0.00%> (ø)
ignite/cmd/network_chain_init.go	0.00% <0.00%> (ø)
ignite/cmd/network_chain_prepare.go	0.00% <0.00%> (ø)
ignite/cmd/network_chain_show_genesis.go	0.00% <0.00%> (ø)
ignite/services/chain/chain.go	6.46% <0.00%> (+0.21%)	⬆️
ignite/services/chain/init.go	0.00% <0.00%> (ø)
ignite/services/chain/serve.go	0.00% <0.00%> (ø)
ignite/services/network/networkchain/init.go	0.00% <0.00%> (ø)
...nite/services/network/networkchain/networkchain.go	0.00% <0.00%> (ø)
... and 1 more