Azure.SDK.Management.ChangelogGen_1.0.0-dev.20230605.1

Add tool to generate changelog for Azure SDK for Dotnet (#6033)

* Initial check-in for ChangelogGen (Tool to generate changelog for Azure SDK for Dotnet Mgmt plane)

* add support of api-version tag

* Update test for api-version tag

* add a simple readme.md

* 1. Only list obsoleted API change
2. Change merge mode from group to line
3. for GA release, the previous GA release will be used as baseline

* Update code per PR comments.

* fix ci after moving to tools folder

* Update readme file for supporting DataPlane in the next step

* Update markdown format of readme.md

* Update markdown format of readme.md2

* Update markdig to signed version

* include static method/property/type in the api compare

* rename folder to changelog-gen-for-net under tools\

* remove breaking changes from preview version

* 1. rename folder name to net-changelog-gen-mgmt
2. improve log
3. support same version of last release as the given one to improve the re-run user experience

* 1. shortcut api comparison for preview version which is not needed
2. fix a bug in method default value check