flowinfra: hydrate types for the inbound streams

[yuzefovich]

The inbound stream handler receives the type information as metadata (unlike other components of the row-based flows), and we forgot to do the hydration of those types. The impact is limited though - the types are only used in a single place when verbose logging is enabled on inbound file (but it could lead to a crash when a user-defined type was encountered).

Fixes: #85447.

Release note: None

[cockroach-teamcity]

This change is 

[yuzefovich]

TFTR!

bors r+

[craig[bot]]

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