Trace Logging on Permission Denied & ColorFormat

[zeripath]

This PR adds log.Trace(...) calls to Permission Denied events.

It also adds a new additional way for providing colored logs for structs in a semi-standardised way. e.g.

log.Info("Log me a user %-v", user)

Will log Log me a user userID:username with the userID being colored cyan and the username in bold.

Structs that want to implement this need to provide a ColorFormat(s fmt.State) function which is very similar to the Format(...) function expected by fmt (mainly lacking the rune - which would always be 'v'.) If you logged %-v then this function will be called, and if more verbose output is possible a + should be passed in the flags and inspected for with s.Flags('+') in ColorFormat, e.g. log.Info("%-+v", perm) to log a verbose version of models.Permission.

[codecov-io]

Codecov Report

Merging #6618 into master will decrease coverage by 0.06%.
The diff coverage is 26.72%.

@@            Coverage Diff             @@
##           master    #6618      +/-   ##
==========================================
- Coverage   40.79%   40.73%   -0.07%     
==========================================
  Files         421      421              
  Lines       57570    57866     +296     
==========================================
+ Hits        23487    23569      +82     
- Misses      30955    31168     +213     
- Partials     3128     3129       +1

Impacted Files	Coverage Δ
routers/repo/issue_watch.go	0% <0%> (ø)	⬆️
routers/api/v1/repo/pull.go	17.58% <0%> (-0.13%)	⬇️
modules/context/permission.go	20.63% <0%> (-20%)	⬇️
routers/repo/issue.go	35.75% <0%> (-1.4%)	⬇️
models/org_team.go	50.38% <0%> (-0.69%)	⬇️
routers/api/v1/api.go	69.78% <0%> (-5.54%)	⬇️
routers/repo/wiki.go	49.68% <0%> (-1.27%)	⬇️
routers/user/home.go	38.03% <0%> (-0.58%)	⬇️
routers/repo/pull.go	36.13% <0%> (-0.54%)	⬇️
models/user.go	50.51% <100%> (+0.18%)	⬆️
... and 11 more

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[techknowlogick]

One nit. Looks good otherwise.

[adelowo]

Isn't Trace implementation supposed to be a no-op if !log.IsTrace rather than check if it's Trace level all the time ?

[zeripath]

Ah yes but constructing the trace call is not free - so if we can avoid constructing it at all that may make sense.

A lot of the calls there are less complex than I originally had them because I moved functionality into colorformat, so we could remove a few of the IsTrace calls but not all