Add pipeline template capability for easy switching between depending on NuGet package vs using `dotnet run`

Sometimes we need to be able to repro and quickly iterate and debug changes to our tools, by editing them and then running relevant pipelines that execute them. But often our pipelines do not depend on given tool directly, but instead on a NuGet package. Hence it is not possible to quickly iterate - one would have to first either push updated package to the feed and then depend on it from the Git branch used for debugging / local experimentation, or make ad-hoc changes to the pipeline to use `dotnet run` instead of the NuGet package.

This work item is about adding support to our pipeline templates for easy switching between using NuGet package and doing `dotnet run`. E.g. using some kind of template that by default uses NuGet package, but if you pass as param a flag like `useDotnetRun: true` it depends on the tool directly.

For examples of how such ad hoc changes were made, see:
- https://github.com/Azure/azure-sdk-tools/blob/4e0fe68723cb3450148989beac2a8ebe8a4e8b6c/tools/pipeline-owners-extractor/Azure.Sdk.Tools.PipelineOwnersExtractor/Program.cs#L67-L73
- By @hallipr: https://github.com/Azure/azure-sdk-tools/commit/8e5bb5412881211280e393a3fe3b1c6ab6c06f97#diff-ac9635b5cec4aa4ae342e27a0b3d2dc3f1a2c8b4ec552817b440cd1b26078281
- By @konrad-jamrozik: https://github.com/Azure/azure-sdk-tools/commit/f55098fe5f2c5d906d7f63afa7d16c02af3676a2#diff-ac9635b5cec4aa4ae342e27a0b3d2dc3f1a2c8b4ec552817b440cd1b26078281