fix: remove duplicate ComponentModelTypeConverter

[kentcb]

What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

fix

What is the current behavior? (You can also link to an open issue here)

The ReactiveUI.Wpf project includes ComponentModelTypeConverter even though it's already in ReactiveUI.

What is the new behavior (if this is a feature change)?

Remove ComponentModelTypeConverter from ReactiveUI.WPF. Also, fix comments in the copy inside ReactiveUI because it actually has nothing to do with WPF.

What might this PR break?

Nothing realistic.

Please check if the PR fulfills these requirements

• The commit follows our guidelines: https://github.com/reactiveui/reactiveui#contribute
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

Other information:

[dnfclas]

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[coveralls]

Changes Unknown when pulling 88a668b on kentcb:component-model-type-converter into ** on reactiveui:develop**.