Preserve case sensitivity in table schema

MySQL and Dolt differ in their preservation of case in the definition of schema:

MySQL:
```sql
mysql> create table t (a int default (now()));
Query OK, 0 rows affected (0.01 sec)

mysql> show create table t;
+-------+-----------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+-------+-----------------------------------------------------------------------------------------------------------------+
| t | CREATE TABLE `t` (
`a` int DEFAULT (now())
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci |
+-------+-----------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
```
Dolt
```sql
dolt> create table t (a int default (now()));
dolt> show create table t;
+-------+------------------------------------------------------------------+
| Table | Create Table |
+-------+------------------------------------------------------------------+
| t | CREATE TABLE `t` ( |
| | `a` int DEFAULT (NOW()) |
| | ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_bin |
+-------+------------------------------------------------------------------+
1 row in set (0.00 sec)
```

Note that `now()` is presenting as `NOW()`

Related: https://github.com/dolthub/dolt/pull/5602

And Capture from discussion with @zachmu :

_preserving case is not always easy, because there are multiple places in the parsing / analysis process where things get normalized functions are especially bad about this
the parser normalizes some of them, and then the analyzer does so again when it resolves a function name to its implementing class
you lose the original case in 2 places sometimes
fixing it everywhere is probably a big lift, but should be the longer term goal_