Fix INSERT SELECT incorrectly fills MATERIALIZED column based of Nullable column

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Changelog category (leave one):

• Bug Fix (user-visible misbehaviour in official stable or prestable release)

Changelog entry (a user-readable short description of the changes that goes to CHANGELOG.md):
Fix INSERT SELECT incorrectly fills MATERIALIZED column based of Nullable column

Detailed description / Documentation draft:
Required columns of the default expression should not be converted to NULL,
since this map value to default and MATERIALIZED values will not work.

Consider the following structure:

• A Nullable(Int64)
• X Int64 materialized coalesce(A, -1)

With recursive_null_as_default=true you will get:

_CAST(coalesce(A, -1), 'Int64') AS X, NULL AS A

And this will ignore default expression.

Fixes: #23524 (Cc: @kssenii)
Fixes: #29729 (Cc: @tavplubix)
Backport: 21.7+

[azat]

Marker check — 5 checks failed (max 5)

I wish this PR has force test label (there was few flaky tests that had been fixed recently), but let's do a rebase (since fixes had been merged already).

[azat]

ClickHouse special build check — 6/7 builds are OK

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Functional stateless tests (release) — fail: 1, passed: 3463

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Functional stateless tests (thread) — Timeout, fail: 3, passed: 928, skipped: 3, unknown: 9

• Reduce memory usage for TSan build by flushing shadow memory #30009