Add support for VALUES statement

[krishvishal]

Current:

limbo> VALUES
('Monty Python and the Holy Grail', 1975, 8.2),
('And Now for Something Completely Different', 1971, 7.5);
thread 'main' panicked at core/translate/select.rs:336:14:
not yet implemented
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

After this PR:

Limbo v0.0.15
Enter ".help" for usage hints.
Connected to a transient in-memory database.
Use ".open FILENAME" to reopen on a persistent database
limbo> VALUES
('Monty Python and the Holy Grail', 1975, 8.2),
('And Now for Something Completely Different', 1971, 7.5);
Monty Python and the Holy Grail|1975|8.2
And Now for Something Completely Different|1971|7.5

limbo> SELECT * FROM (VALUES (1, 2, 'VALUES'));
1|2|VALUES

Fixes: #866

[krishvishal]

I can't reproduce the failing fuzz test on my local machine. The failure seems to be related to how string concatenation is handled in limbo and unrelated to the current PR. I will look into it in a separate PR.

[pedrocarlo]

@krishvishal have a look at #1021 and #1038 to see your particular error is fixed there. I am trying to fix some text_casts and @jussisaurio was trying to fix a whole lot more in his.

[krishvishal]

@krishvishal have a look at #1021 and #1038 to see your particular error is fixed there. I am trying to fix some text_casts

@pedrocarlo thanks for sharing this.

[krishvishal]

@penberg requesting review.

[jussisaurio]

I feel like we shouldn't need separate specialcasing to handle this. What about e.g. SELECT * from sometable JOIN (VALUES (1),(2),(3))?

It seems VALUES with multiple rows is quite similar to how subqueries work.