feat: add search text-sql pair in cached table

[jitingxu1]

Related issue: #46

Search question to check if it is in the cached table.

• pass a cached Table
  • schema: question, sql, dialect
• create a search-text-task
  • search the cached table by calculating the levenshtein normalized edit distance
• search question before generating sql by LLM

---

ADDED

from ibis_birdbrain.bot import Bot
import ibis
ibis.options.interactive = True

con = ibis.duckdb.connect()
t = ibis.read_parquet("m.parquet")
con.create_table("mortgage", t.to_pyarrow())


questions = [
    {
        "question": "how many rows in the table",
        "sql": "select count(*) from mortgage",
        "dialect": "duckdb",
    },
    {
        "question": "top 10 rows in the table",
        "sql": "select * from mortgage limit 10",
        "dialect": "duckdb",
    },
]
cached_table = ibis.memtable(questions)
bot = Bot(con=con, cached_table=cached_table)

bot("top 10 rows in the table")

[drabastomek]

Some small things. The rest LGTM.

[lostmygithubaccount]

merging, thanks!