Reexported integration algorithms

using SciMLExpectations also brings the integration algorithm selectors accepted by the quadalg keyword into scope. The names are owned and documented by Integrals.jl and its backends:

• Built-in and pure-Julia algorithms: ArblibJL, FastTanhSinhQuadratureJL, GaussLegendre, HAdaptiveIntegrationJL, HCubatureJL, QuadGKJL, QuadratureRule, SimpsonsRule, and TrapezoidalRule
• Cuba algorithms: CubaCuhre, CubaDivonne, CubaSUAVE, and CubaVegas
• Cubature algorithms: CubatureJLh and CubatureJLp
• VEGAS algorithms: VEGAS and VEGASMC
• Domain transformation: ChangeOfVariables

The corresponding backend package must still be loaded when an algorithm requires one. Anything else from Integrals must be imported from Integrals directly.