Update nuspec to place library under nano TFM

[Copilot]

The nuspec file was placing compiled artifacts directly under lib\ and declaring a bare dependency instead of a TFM-scoped group, which is incorrect for nanoFramework packages.

Changes

• Dependency group: Wrapped nanoFramework.CoreLibrary in <group targetFramework=".NETnanoFramework1.0"> to properly declare the nanoFramework TFM dependency group.
• Files: Replaced five individual file entries (.dll, .pdb, .pdbx, .pe, .xml) with a single wildcard entry targeting lib\netnano1.0.

<!-- Before -->
<dependencies>
  <dependency id="nanoFramework.CoreLibrary" version="2.0.0-preview.35" />
</dependencies>
<files>
  <file src="System.Device.I2c\bin\Release\System.Device.I2c.dll" target="lib\System.Device.I2c.dll" />
  <file src="System.Device.I2c\bin\Release\System.Device.I2c.pdb" target="lib\System.Device.I2c.pdb" />
  ...
</files>

<!-- After -->
<dependencies>
  <group targetFramework=".NETnanoFramework1.0">
    <dependency id="nanoFramework.CoreLibrary" version="2.0.0-preview.35" />
  </group>
</dependencies>
<files>
  <file src="System.Device.I2c\bin\Release\System.Device.I2c.*" target="lib\netnano1.0" />
  ...
</files>

Pattern follows the reference from nanoframework/System.Device.Adc@aab7bca.

Original prompt

---

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.

Description

</issue_description>

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

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