[Feature Request]: Add scope type display

[inahiki-dev]

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Description

In the messages file, there is a variables %SCOPE% that replaces categories and servers with the prefixes category: and server:. I couldn't find a way to remove or customize these prefixes. I suggest adding the ability to modify the prefix patterns. For example:

scope-display:
    global: 'All servers' # from <global-scope-display>
    category-prefix: '[Category]: '
    server-prefix: '[Server]: '