feat: Introduce BooleanT and boolean functions (#17)

This PR adds a boolean section, as well as an isNaN predicate on numbers. In a TypeDispatcher, when BooleanT is present, isNaN returns a BooleanT. However, in a numbers-only TypeDispatcher, it returns 1 or 0 instead. Moreover, when booleans are subsequently added to a numbers-only instance, isNaN properly reconfigures itself to return BooleanT.

No predicates that depend on approximate equality testing or a configuration object are implemented in this PR.

This PR also implements type matching and dispatching with implicit conversions, and adds an implicit conversion from BooleanT to NumberT.

Reviewed-on: #17
Co-authored-by: Glen Whitney <glen@studioinfinity.org>
Co-committed-by: Glen Whitney <glen@studioinfinity.org>

src/number/__test__/utils.spec.js

@@ -5,4 +5,9 @@ describe('number utilities', () => {
    it('clones a number', () => {
       assert.strictEqual(math.clone(2.637), 2.637)
    })
+   it('tests if a number is NaN', () => {
+      assert.strictEqual(math.isnan(NaN), true)
+      assert.strictEqual(math.isnan(Infinity), false)
+      assert.strictEqual(math.isnan(43), false)
+   })
 })