Add check that Dict/RLE for strings is the first filter in the pipeline; allow use w/ other filters

[ihnorton]

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TYPE: FEATURE DESC: Add check that Dict/RLE for strings is the first filter in the pipeline; allow use w/ other filters

[shortcut-integration[bot]]

This pull request has been linked to Shortcut Story #21346: Dictionary filter should only require first slot in pipeline, not exclude other filters.