Only check MV on ALTER when necessary

[Algunenano]

Changelog category (leave one):

• Performance Improvement

Changelog entry (a user-readable short description of the changes that goes to CHANGELOG.md):

• Only check dependencies if necessary when applying ALTER TABLE queries.

Documentation entry for user-facing changes

Since forever (all supported releases), when CH wants to do an ALTER over a table it calls getDependentViewsByColumn to check the columns used by dependencies (materialized views, etc). My guess is that in order to avoid calling this multiple times in an execution it was moved outside of the loop, but this means that unrelated alters might check dependencies which can be really expensive.

For example, if you modify a table TTL and that table has 100 MV pending from it you will have 100 checks which are unnecessary.

[Algunenano]

AST Fuzzer -> #48148