Merge 'Centralize Rust integration and regression tests' from Sonny

## What?
- centralized Rust integration and regression tests
- no new tests added
- no tests removed
- only refactored tests into modules and common utils
## Why?
- @penberg and I have a discussion [here](https://github.com/tursodataba
se/limbo/pull/694#discussion_r1921949665) about centralizing the
integration/ regression tests so that they are not scattered around.
- this is a PR to do that and some refactor of the existing tests to
make the structure easier to navigate + add new tests in the future.

Reviewed-by: Jussi Saurio (@jussisaurio)
Reviewed-by: Preston Thorpe (@PThorpe92)
Reviewed-by: Pere Diaz Bou (@pereman2)

Closes #753

Cargo.toml

@@ -15,7 +15,8 @@ members = [
     "macros",
     "simulator",
     "sqlite3",
-    "test", "extensions/percentile",
+    "tests",
+    "extensions/percentile",
 ]
 exclude = ["perf/latency/limbo"]
 

cli/Cargo.toml

@@ -32,8 +32,3 @@ miette = { version = "7.4.0", features = ["fancy"] }
 
 [features]
 io_uring = ["limbo_core/io_uring"]
-
-# not testing the cli on windows as rexpect does not support it.
-[target.'cfg(not(windows))'.dev-dependencies]
-assert_cmd = "^2"
-rexpect = "0.6.0"