Consistency in error CodespaceType

[kwunyeung]

I found that the CodespaceType used in errors are not consistent in different modules. All modules are using lowercase module name but distr module is using DISTR.

cosmos-sdk/x/distribution/types/errors.go

Line 11 in 0684a42

DefaultCodespace sdk.CodespaceType = "DISTR"

Should all CodespaceType just use the module name like slashing does?

cosmos-sdk/x/slashing/errors.go

Line 13 in cff985f

DefaultCodespace sdk.CodespaceType = ModuleName

[alexanderbez]

Good catch @kwunyeung!