UPDATE: Adds 56 functions in the Statistical section

Uses statrs for numerical functions

REFACTOR: Put statistical functions on its own module

This might seem counter-intuitive but the wasm build after this refactor
is 1528 bytes smaller :)

base/src/test/statistical/test_fn_f.rs

@@ -0,0 +1,75 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn test_fn_f_dist_sanity() {
+    let mut model = new_empty_model();
+    model._set("A1", "=F.DIST(15, 6, 4, TRUE)");
+    model._set("A2", "=F.DIST(15, 6, 4, FALSE)");
+    model._set("A3", "=F.DIST(15, 6, 4)");
+    model._set("A4", "=F.DIST(15, 6, 4, TRUE, FALSE)");
+    model.evaluate();
+    assert_eq!(model._get_text("A1"), *"0.989741952");
+    assert_eq!(model._get_text("A2"), *"0.001271447");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+    assert_eq!(model._get_text("A4"), *"#ERROR!");
+}
+
+#[test]
+fn test_fn_f_dist_rt_sanity() {
+    let mut model = new_empty_model();
+
+    // Valid call
+    model._set("A1", "=F.DIST.RT(15, 6, 4)");
+    // Too few args
+    model._set("A2", "=F.DIST.RT(15, 6)");
+    // Too many args
+    model._set("A3", "=F.DIST.RT(15, 6, 4, 1)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"0.010258048");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+}
+
+#[test]
+fn test_fn_f_inv_sanity() {
+    let mut model = new_empty_model();
+
+    // Valid call: left-tail inverse
+    model._set("A1", "=F.INV(0.9897419523940, 6, 4)");
+
+    // Too many args
+    model._set("A2", "=F.INV(0.5, 6, 4, 2)");
+
+    // Too few args
+    model._set("A3", "=F.INV(0.5, 6)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"15");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+}
+
+#[test]
+fn test_fn_f_inv_rt_sanity() {
+    let mut model = new_empty_model();
+
+    // Valid call: left-tail inverse
+    model._set("A1", "=F.INV.RT(0.0102580476059808, 6, 4)");
+
+    // Too many args
+    model._set("A2", "=F.INV.RT(0.5, 6, 4, 2)");
+
+    // Too few args
+    model._set("A3", "=F.INV.RT(0.5, 6)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"15");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+}