refactor: replace unix time stamps

[aljo242]

Closes #913

The only remaining time that is not time.Time or time.Duration is in proto/types/ibc.proto, where a timestamp is saved as a string. I wasn't sure what we wanted to do with this one.

[codecov]

Codecov Report

Merging #948 (a5ccf87) into develop (aab4d3d) will decrease coverage by 0.00%.
The diff coverage is 6.52%.

@@             Coverage Diff             @@
##           develop     #948      +/-   ##
===========================================
- Coverage    10.66%   10.66%   -0.01%     
===========================================
  Files          272      272              
  Lines        64942    64990      +48     
===========================================
  Hits          6929     6929              
- Misses       57850    57898      +48     
  Partials       163      163              

Impacted Files	Coverage Δ
x/campaign/types/vesting.pb.go	2.37% <0.00%> (-0.08%)	⬇️
x/launch/types/events.pb.go	0.49% <0.00%> (-0.01%)	⬇️
x/launch/types/vesting_account.pb.go	1.80% <0.00%> (-0.05%)	⬇️
x/campaign/types/share_vesting_options.go	100.00% <100.00%> (ø)
x/launch/keeper/msg_trigger_launch.go	100.00% <100.00%> (ø)
x/launch/keeper/request.go	100.00% <100.00%> (ø)
x/launch/types/vesting_options.go	93.75% <100.00%> (ø)

[lumtis]

The only remaining time that is not time.Time or time.Duration is in proto/types/ibc.proto, where a timestamp is saved as a string. I wasn't sure what we wanted to do with this one.

We can actually let the string

The reason is we want the ConsensusState type to be directly the unmarshaled version of the consensus state file dumped by the ibc CLI query

[lumtis]

LGTM