Show tables does not respect database scope

[rjatwal]

What happens?

Show table is not currently limited to a single database.

To Reproduce

 ./duckdb -unsigned
v0.7.2-dev899 88b1bfa74d
Enter ".help" for usage hints.
D attach 'db1.db';
D attach 'db2.db';
D  create table db1.table_in_db1(i int);
D create table db2.table_in_db2(i int);
D show tables;
┌──────────────┐
│     name     │
│   varchar    │
├──────────────┤
│ table_in_db1 │
│ table_in_db2 │
└──────────────┘
D use db1;
D show tables;
┌──────────────┐
│     name     │
│   varchar    │
├──────────────┤
│ table_in_db1 │
│ table_in_db2 │
└──────────────┘
D
``

### OS:

linux

### DuckDB Version:

v0.7.1

### DuckDB Client:

CLI

### Full Name:

RJ Atwal

### Affiliation:

MotherDuck

### Have you tried this on the latest `master` branch?

- [X] I agree

### Have you tried the steps to reproduce? Do they include all relevant data and configuration? Does the issue you report still appear there?

- [X] I agree

[rjatwal]

#6816

[Mytherin]

Should be fixed now