sqlite3 completion fail on attached names with quotes

Bug report

Bug description:

Tab completion fails in sqlite3 when the name of an attached DB contains a quote.

Minimal code repro:

import sqlite3
from sqlite3._completer import _complete

con = sqlite3.connect(":memory:")
con.execute("""ATTACH ':memory:' AS [has"quote]""")
con.execute("""CREATE TABLE [has"quote].example_table(value)""")
print(_complete(con, "exam", 0)) # sqlite3.OperationalError: unrecognized token: "".sqlite_master
con.close()

Minimal CLI repro if you prefer:

(open the CLI)
>>> <python executable≥ -m sqlite3
(in CLI):
>>> ATTACH ':memory:' AS "has""quote";
>>> CREATE TABLE "has""quote".example_table(value);
>>> SELECT * FROM exam<press tab here and it doesn't work>

CPython versions tested on:

CPython main branch, 3.15

Operating systems tested on:

macOS

Linked PRs

• gh-153770

从 sqlite3._completer._complete 开始，使用 issue 中的 Python 或 CLI 示例，复现附加数据库名称包含引号时的失败。跟踪补全路径，直到生成的 SQLite 查询失败。对于包含引号的附加名称，Tab 补全能够成功执行且不出现 unrecognized-token 错误，即表示完成。