Refactor Microsoft.Quantum.Simulation and Microsoft.Quantum.AmplitudeAmplification to use style guide.

[cgranade]

Is your feature request related to a problem? Please describe.
With resolving #35 in April, we made a lot of progress on making the libraries more consistent, more discoverable, and easier to use. It would be good to continue that effort by using new Q# features like UDT named items, namespace aliases, and attributes (microsoft/qsharp-compiler#169) to make the APIs for data structures in the simulation and amplitude amplification namespaces easier to use.

This would also be a good chance to improve further our consistency with the Q# style guide, parallel to efforts such as microsoft/QuantumKatas#110.

Describe the solution you'd like

• Remove AmpAmp prefix from function and operation names in Microsoft.Quantum.AmplitudeAmplification (redundant with namespace name).
• Rename functions in Microsoft.Quantum.AmplitudeAmplification to use only noun or adjective pharases.
• Rename operations in Microsoft.Quantum.AmplitudeAmplification to use only verb phrases.
• Ensure that UDTs in Microsoft.Quantum.AmplitudeAmplification have named items.
• Refactor Microsoft.Quantum.Simulation to move all type conversion functions that act on basic types to Microsoft.Quantum.Convert, use XAsY naming scheme.
• Refactor Microsoft.Quantum.Simulation to rename type conversion functions specific to simulation data to use XAsY naming scheme.
• Ensure that UDTs in Microsoft.Quantum.Simulation have named items.
• Remove "accessor functions" such as GetGeneratorSystemFunction in favor of UDT named item accessor notation.

[cgranade]

+@guanghaolow for feedback.