Is your feature request related to a problem or challenge? Please describe what you are trying to do.
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(This section helps Arrow developers understand the context and why for this feature, in addition to the what)

Describe the solution you'd like
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Currently the substring function only support "plain" arrays, but not DictionaryArray - for the latter we should be able to apply substring directly on the dictionary values.

Describe alternatives you've considered
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No

Additional context
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N/A