Initialized the settlement client with the proposer upon initialization

[omritoptix]

and refactored the settlement client to be more testable.

[codecov]

Codecov Report

Merging #168 (9c44d15) into main (8ec3b08) will decrease coverage by 1.55%.
The diff coverage is 27.65%.

@@            Coverage Diff             @@
##             main     #168      +/-   ##
==========================================
- Coverage   55.02%   53.46%   -1.56%     
==========================================
  Files          60       66       +6     
  Lines       11014    11793     +779     
==========================================
+ Hits         6060     6305     +245     
- Misses       4083     4584     +501     
- Partials      871      904      +33     

Impacted Files	Coverage Δ
settlement/dymension/cosmosclient.go	0.00% <0.00%> (ø)
settlement/events.go	100.00% <ø> (ø)
settlement/settlement.go	0.00% <0.00%> (ø)
mocks/settlement/rollapp_query_client.go	2.22% <2.22%> (ø)
mocks/settlement/sequencer_query_client.go	12.06% <12.06%> (ø)
mocks/cosmosclient.go	18.96% <18.96%> (ø)
settlement/dymension/dymension.go	22.26% <22.26%> (ø)
mocks/settlement/hubclient.go	34.04% <34.04%> (ø)
settlement/mock/mock.go	70.11% <75.47%> (+8.84%)	⬆️
settlement/base.go	78.03% <78.03%> (ø)
... and 3 more

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more