(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

auto filter_type = node.result_type;
    if (!filter_type->canBeUsedInBooleanContext())
        throw Exception("Invalid type for filter in PREWHERE: " + filter_type->getName(),
                        ErrorCodes::ILLEGAL_TYPE_OF_COLUMN_FOR_FILTER);
    {
        
        auto tmp_actions_dag = std::make_shared<ActionsDAG>(sourceColumns());
        getRootActions(select_query->prewhere(), only_types, tmp_actions_dag);
        tmp_actions_dag->removeUnusedActions(NameSet{prewhere_column_name});
        auto tmp_actions = std::make_shared<ExpressionActions>(tmp_actions_dag, ExpressionActionsSettings::fromContext(getContext()));
        auto required_columns = tmp_actions->getRequiredColumns();
        NameSet required_source_columns(required_columns.begin(), required_columns.end());
        required_source_columns.insert(first_action_names.begin(), first_action_names.end());
        
        
        for (const auto & column : additional_required_columns)
        {
            if (required_source_columns.count(column))
                step.addRequiredOutput(column);
        }
        auto names = step.actions()->getNames();
        NameSet name_set(names.begin(), names.end());
        for (const auto & column : sourceColumns())
            if (required_source_columns.count(column.name) == 0)
                name_set.erase(column.name);
        Names required_output(name_set.begin(), name_set.end());
        prewhere_actions = chain.getLastActions();
        prewhere_actions->removeUnusedActions(required_output);
    }
    {