Distinguish between SQL query and fragment (#429)
BREAKING CHANGE:
### Replaces `sql` tagged template literal with `sql.fragment`.
Before:
```ts
const where = sql`WHERE bar = 1`
sql`
SELECT 1
FROM foo
${where}
`
```
After:
```ts
const where = sql.fragment`WHERE bar = 1`
sql.fragment`
SELECT 1
FROM foo
${where}
`
```
### SQL fragments cannot be used as queries; use `sql.type` instead
Before:
```ts
connection.query(sql`
SELECT 1
FROM foo
`)
```
After:
```ts
connection.query(sql.type({
id: z.object({
id: z.number(),
})
})`
SELECT 1 AS id
FROM foo
`)
```
### Adds `sql.unsafe` (shortcut to `sql.type(z.any())`)
Before:
```ts
connection.query(sql`
SELECT 1
FROM foo
`)
```
After:
```ts
connection.query(sql.unsafe`
SELECT 1
FROM foo
`)
```
### Query methods can no longer by typed, i.e. `connection.one<Row>()` needs to be replaced with `connection.one(sql.type()``)`.
Before:
```ts
connection.oneFirst<number>(sql`
SELECT 1
FROM foo
`)
```
After:
```ts
connection.oneFirst(sql.typeAlias('id')`
SELECT 1 AS id
FROM foo
`)
```
