Improvement on texts and error behaviours on /todo settings

[larkox]

Summary

Improve the texts and error messages/behaviours on /todo settings

Current look:

/todo settings

/todo settings summ

/todo settings summary

/todo settings summary on

/todo settings summary off

/todo settings summary foo

/todo settings summary on foo

Ticket Link

None

[asaadmahmood]

@larkox Can we format the Invalid input on/off like we did above? (in code blocks).

[asaadmahmood]

Also, we need a full stop after the end of each error.
i.e. "Error: Too many arguments."
And can we make that error text use our error color?
And then we can probably even remove the "Error" at the start.

[codecov-commenter]

Codecov Report

Merging #110 into master will decrease coverage by 0.02%.
The diff coverage is 60.00%.

@@            Coverage Diff            @@
##           master    #110      +/-   ##
=========================================
- Coverage    3.77%   3.75%   -0.03%     
=========================================
  Files           8       8              
  Lines         928     933       +5     
=========================================
  Hits           35      35              
- Misses        893     897       +4     
- Partials        0       1       +1     

Impacted Files	Coverage Δ
server/command.go	11.48% <60.00%> (-0.25%)	⬇️

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[larkox]

@asaadmahmood Sure. Here is a screenshot with the on/off corrected, and a few with the full stop at the end of the sentence.

[asaadmahmood]

@larkox
And can we make that error text use our error color?
And then we can probably even remove the "Error" at the start.

[larkox]

@asaadmahmood We are limited by markdown here. If I remember correctly, there is no markdown to change the color of the text (but would be a nice addition! (as long we keep it to a limited set of colors like error, warning, etc...)).

We could go with Message Attachments, and change the color of the bar on the left, but since we the code is in back-end, I am not sure we can access the theme color for error.

Edit: We can also go with custom post types, but then they will not work on mobile...

[asaadmahmood]

I think we can go with what we have for now then.

[hanzei]

two questions

[jfrerich]

LGTM!

[DHaussermann]

@hanzei or @jfrerich If you have a bit of time, could one of you peer-test this PR using the peer testing process documented here https://mattermost.atlassian.net/wiki/spaces/INT/pages/619937892/Peer+Testing+Process

[DHaussermann]

Tested and passed
Based on code changes, I have reviewed improved error messages shown to the user. No issues found
LGTM!

No changes needed to release testing.