(you don't have to strictly follow this form)

**Describe the bug**
When using `ORDER BY column_name COLLATE 'en'`, `COLLATE` is ignored if `column_name` is the primary key
 
**How to reproduce**
* version 21.1.2
* `CREATE TABLE` statements for all tables involved:
```
CREATE TABLE test.test_collation
(
    `v` String,
    `v2` String
)
ENGINE = MergeTree
ORDER BY v
SETTINGS index_granularity = 8192
```
* Sample data:
```
insert into test.test_collation values ('A', 'A')
insert into test.test_collation values ('B', 'B')
insert into test.test_collation values ('C', 'C')
insert into test.test_collation values ('a', 'a')
insert into test.test_collation values ('b', 'b')
insert into test.test_collation values ('c', 'c')
```
* Queries to run that lead to unexpected result
Primary key
```
SELECT *
FROM test.test_collation
ORDER BY v ASC COLLATE 'en'

Query id: fa84ae7a-abe7-4886-99cd-eba7ad5d5fc4

┌─v─┬─v2─┐
│ A │ A  │
│ B │ B  │
│ C │ C  │
│ a │ a  │
│ b │ b  │
│ c │ c  │
└───┴────┘
```
Separate column
```
SELECT *
FROM test.test_collation
ORDER BY v2 ASC COLLATE 'en'

Query id: 04401f85-3cb2-442c-8c89-e3328d1615cd

┌─v─┬─v2─┐
│ a │ a  │
│ A │ A  │
│ b │ b  │
│ B │ B  │
│ c │ c  │
│ C │ C  │
└───┴────┘
```

**Expected behavior**
Both of these queries to return the rows in the same order

const auto * func = child->as<ASTFunction>();
        if (func && func->name == "lambda")
            continue;
        makeSetsForIndex(child);
    }
    const auto * func = node->as<ASTFunction>();
    if (func && functionIsInOrGlobalInOperator(func->name))
    {
        const IAST & args = *func->arguments;
        const ASTPtr & left_in_operand = args.children.at(0);
        if (storage()->mayBenefitFromIndexForIn(left_in_operand, getContext(), metadata_snapshot))
        {
            const ASTPtr & arg = args.children.at(1);
            if (arg->as<ASTSubquery>() || arg->as<ASTIdentifier>())
            {
                if (settings.use_index_for_in_with_subqueries)
                    tryMakeSetForIndexFromSubquery(arg, query_options);
            }
            else
            {
                auto temp_actions = std::make_shared<ActionsDAG>(columns_after_join);
                getRootActions(left_in_operand, true, temp_actions);
                if (temp_actions->tryFindInIndex(left_in_operand->getColumnName()))
                    makeExplicitSet(func, *temp_actions, true, getContext(),
                        settings.size_limits_for_set, prepared_sets);
            }
        }
    }
}
void ExpressionAnalyzer::getRootActions(const ASTPtr & ast, bool no_subqueries, ActionsDAGPtr & actions, bool only_consts)