Optimization statements performance related to system meta data

## Feature Request

**Is your feature request related to a problem? Please describe:**

This issue will optimize the query performance for metadata-related statements

Scenario1:
```
SELECT column_name
FROM information_schema.statistics
WHERE index_name = 'PRIMARY'
AND table_schema = database()
AND table_name = 'xx'
ORDER BY seq_in_index;
```
Scenario2:
```
SELECT table_comment
FROM information_schema.tables
WHERE table_schema = database() AND table_name = 'xxx'
```
Scenario3:
```
SELECT table_name
FROM information_schema.tables
WHERE table_schema = database() AND table_type = 'xxx'
```

**Describe the feature you'd like:**

Speed up the query for metadata to be executed more quickly.
1. Push down predicates to memTableReader.
2. Do column pruning when reading infoschema.tables.