Support type coercion for structural types in Iceberg and Delta Lake

[ebyhr]

Description

Fixes #21511 Supersedes #21055 with connector side approach

Release notes

(x) Release notes are required, with the following suggested text:

# Section
* TBD. ({issue}`issuenumber`)

[SemionPar]

To avoid conflicts, basing char coercion in Delta (https://github.com/ebyhr/trino/pull/1) on this branch