Kiota Dotnet Mono repo migration - #262

Fixes #238

In Summary changes include

• Restructure csproj file to be simpler to eliminate repeated configs (which are now held in Directory.Build.props)
• Update version stratey to be common accross libs (pulled from Directory.Build.props)
• Updates CI and release pipelines/scripts
• Moves sources of other libraries to be held in one project solution (Microsoft.Kiota) as below

 └─Microsoft.Kiota.sln
 └─src
    └─abstractions
    └─authentication
       └─azure
    └─http
       └─httpClient
    └─serialization
       └─json
       └─form
       └─text
       └─multipart
 └─tests
    └─abstractions
    └─authentication
       └─azure
    └─http
       └─httpClient
    └─serialization
       └─json
       └─form
       └─text
       └─multipart

CI/Validation

• Release pipeline artifacts can be inpected at the run at - https://microsoftgraph.visualstudio.com/Graph%20Developer%20Experiences/_build/results?buildId=155464&view=results
• PR validation at https://github.com/microsoft/kiota-abstractions-dotnet/actions/runs/9837309232/job/27154841826?pr=262

Notes
To separate concerns, sources are migrated as is. Resolving any issues with the source would ideally be done separately.