Replace CommonJS-only dependencies with inline ESM code

## Problem

When using mathjs in an Angular project (and likely other modern ESM-first bundlers), the following warnings are emitted during the build:

```
▲ [WARNING] Module 'seedrandom' used by 'node_modules/mathjs/lib/esm/function/probability/util/seededRNG.js' is not ESM

▲ [WARNING] Module 'escape-latex' used by 'node_modules/mathjs/lib/esm/utils/latex.js' is not ESM

▲ [WARNING] Module 'javascript-natural-sort' used by 'node_modules/mathjs/lib/esm/function/relational/compareNatural.js' is not ESM

▲ [WARNING] Module 'tiny-emitter' used by 'node_modules/mathjs/lib/esm/utils/emitter.js' is not ESM
```

> CommonJS or AMD dependencies can cause optimization bailouts.
> For more information see: https://angular.dev/tools/cli/build#configuring-commonjs-dependencies

## Proposal

All four of these dependencies are tiny libraries that haven't been updated in 7+ years:

| Package | Last publish | Size |
|---|---|---|
| `seedrandom` | 7 years ago | small |
| `escape-latex` | 7 years ago | small |
| `javascript-natural-sort` | 9 years ago | small |
| `tiny-emitter` | 7 years ago | small |

Since they are unmaintained and unlikely to ever ship ESM builds, I'd suggest inlining their code directly into mathjs as proper ESM modules. This would:

1. Eliminate the CommonJS warnings for Angular/esbuild/Vite users
2. Allow tree-shaking to work properly on this code
3. Remove external dependencies that are effectively abandoned

I'll follow up with PRs to inline each of these.