Updated profiles' create and edit

[leobragaz]

Description

This PR merge the current MsgCreateProfile and MsgEditProfile into the new
MsgSaveProfile that handles both the situations.
Closes #170 .

Checklist

• Targeted PR against correct branch.
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Wrote unit tests.
• Wrote integration tests (simulation & CLI).
• Updated the documentation.
• Added an entry to the CHANGELOG.md file.
• Re-reviewed Files changed in the Github PR explorer.

[RiccardoM]

The implementation looks overall good to me. There's only a small change I would do inside the CLI save command

[RiccardoM]

I'm not sure if using get GetString having an empty string works as we would want to. What I was thinking is the following.

Suppose you execute desmoscli tx save --name="Riccardo" then what will happen is that all the remaining fields are rest to "" instead of nil (I've checked and they are two different values). So I think we should change it appropriately.

This could be done by creating the following functions:

// getOrNil returns a pointer to the given value if it is not empty. Otherwise it returns nil
func getOrNil(value string) *string {
  if len(strings.TrimSpace(value)) == 0 {
    return nil
  }
  return &value
}

And use such function as

moniker := getOrNil(viper.GetString(flagMoniker))
name := getOrNil(viper.GetString(flagMoniker))

[leobragaz]

re-reviewed

[codecov]

Codecov Report

Merging #180 into master will decrease coverage by 0.43%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #180      +/-   ##
==========================================
- Coverage   83.12%   82.68%   -0.44%     
==========================================
  Files          58       58              
  Lines        2447     2374      -73     
==========================================
- Hits         2034     1963      -71     
+ Misses        356      355       -1     
+ Partials       57       56       -1