OSOE-852: Change NuGet metadata to use license expressions

[AydinE]

OSOE-852
Use license expression for all nuget packages.

Based on coment here:

• Test the change proposed above with an alpha release of any single-package project first.
• Change all NuGet-published projects of ours.
• Check if lines like <None Include="License.md" Pack="true" PackagePath="" /> can be removed from csprojs too; most possibly yes, then remove them.
• Update our documentation.

Did an initial alpha release of: Lombiq/Orchard-Azure-Application-Insights#88
v8.0.2-alpha.2.osoe-852 as a test see: https://www.nuget.org/packages/Lombiq.Hosting.Azure.ApplicationInsights/8.0.2-alpha.2.osoe-852

Only thing I am not sure of is what "Update our documentation" which documentations are meant exactly?
Updated docs

See:
Lombiq/PowerShell-Analyzers#41
Lombiq/Orchard-Azure-Application-Insights#88
Lombiq/Helpful-Libraries#269
Lombiq/Orchard-Core-API-Client#50
Lombiq/Audit-Trail-Extensions#32
Lombiq/Orchard-Chart.js#77
Lombiq/Orchard-Content-Editors#70
Lombiq/Orchard-Data-Tables#167
Lombiq/Helpful-Extensions#172
Lombiq/Hosting-Build-Version-Display#25
Lombiq/Hosting-Tenants#124
Lombiq/Orchard-JSON-Editor#65
Lombiq/Orchard-Login-as-Anybody#12
Lombiq/Orchard-Privacy#91
Lombiq/Orchard-UIKit#63
Lombiq/Orchard-Vue.js#142
Lombiq/Orchard-Walkthroughs#17
Lombiq/Orchard-Base-Theme#120
Lombiq/Hosting-Media-Theme#67
Lombiq/NodeJs-Extensions#102
Lombiq/NPM-Targets#37
Lombiq/Setup-Extensions#34
Lombiq/Testing-Toolbox#42
Lombiq/UI-Testing-Toolbox#379
Lombiq/.NET-Analyzers#102
Fixes #761

[Piedone]

You don't need to link submodules under OSOCE PRs BTW, since they'll show up under the Jira issue.