Log the start of Static Graph construction

[abulyaev]

Fixes #11166

Context

Changes Made

Log message added

Testing

One test was updated to reflect the change

Notes

[abulyaev]

@abulyaev please read the following Contributor License Agreement(CLA). If you agree with the CLA, please reply with the following information.

@dotnet-policy-service agree [company="{your company}"]

Options:

• (default - no company specified) I have sole ownership of intellectual property rights to my Submissions and I am not making Submissions in the course of work for my employer.

@dotnet-policy-service agree

• (when company given) I am making Submissions in the course of work for my employer (or my employer has intellectual property rights in my Submissions by contract or applicable law). I have permission from my employer to make Submissions and enter into this Agreement on behalf of my employer. By signing below, the defined term “You” includes me and my employer.

@dotnet-policy-service agree company="Microsoft"

Contributor License Agreement

@dotnet-policy-service agree

[rainersigwald]

My only question is what log importance level this should be. In @jeffkl's example where constructing the graph takes 30s, it'd be really nice to see it! But in a lot of smaller repos I'd rather avoid a log line like this.

@baronfel do you have opinions?

I kinda want a deferred message, where we log nothing unless it takes 5s (or something) and then log at high pri. But we don't have anything else that works like that and it sounds kinda annoying!