Make `fuga` and rewrite functions' front-end

[Axect]

Description

After Ver 0.23.0, peroxide will use two different main modules - prelude and fuga.

• prelude: Contains all simplified functions. (ex: a.norm(), integrate(f, (a,b)))
• fuga: Contains all customizable functions. (ex: a.norm(L2), integrate(f, (a,b), GaussLegendre(15)))

Fuga list

• [x] Norm
  • [x] Vector norm
  • [x] Matrix norm
• [x] Solve
  • [x] LU
  • [x] WAZ
  • [ ] QR
• [x] Integrate
• [x] Spline
• [x] ODE