Update nuspec to place library under nano TFM

[Copilot]

NuGet packages were placing assemblies directly under lib\ instead of the correct lib\netnano1.0\ TFM subfolder, and dependencies lacked a .NETnanoFramework1.0 target framework group declaration.

Changes to nanoFramework.System.Device.UsbStream.nuspec

• Dependencies: Wrapped all dependencies in <group targetFramework=".NETnanoFramework1.0">
• Files: Collapsed five individual file entries into a single wildcard targeting lib\netnano1.0

<dependencies>
  <group targetFramework=".NETnanoFramework1.0">
    <dependency id="nanoFramework.CoreLibrary" version="2.0.0-preview.35" />
    <dependency id="nanoFramework.System.IO.Streams" version="2.0.0-preview.10" />
    <dependency id="nanoFramework.Runtime.Events" version="2.0.0-preview.8" />
  </group>
</dependencies>
...
<file src="System.Device.UsbStream\bin\Release\System.Device.UsbStream.*" target="lib\netnano1.0" />

Original prompt

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This section details on the original issue you should resolve

<issue_title>Update nuspec to place library under nano TFM</issue_title>
<issue_description>### Details about task
Most of the nuspec files are not using the correct location to place the files.
Files (DLL, PE, PDBX and XML for IntelliSense) should be placed under "lib\netnano1.0" (currently are being placed under "lib" only.
Also they should declare a dependency group for ".NETnanoFramework1.0" target framework.
At the same time those still naming the various file types should use a wildcard instead (e.g. "...\Release\mscorlib.*).
The correct pattern should be (take this nuspec as sample):
nanoframework/System.Device.Adc@aab7bca

Do not change anything else on the nuspec file.

Work from the DEVELOP branch.

Description

</issue_description>

Comments on the Issue (you are @copilot in this section)

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