Delimiting tag set headers

[rcj1]

This PR is intended to indent tag sets such as those under gc.heap.generation by one extra indent. This makes it clearer that the label gc.heap.generation is a header and not a data value.

Before:

After:

closes #4935

[noahfalk]

Have you tried visualizing the "Microsoft.AspNetCore.Hosting" provider on a .NET web app? That shows an example of metrics with quite a few dimensions. I'm guessing this extra indent is a tradeoff between making the headers clearer when there are fewer dimensions vs. taking more horizontal space for cases with large numbers of dimensions. As long as the high dimension cases still look OK then tab is great. If high dimension cases don't look good any more than we might want to consider other options like smaller spacing or using "-----" to underline column headers instead.

https://learn.microsoft.com/en-us/aspnet/core/log-mon/metrics/metrics?view=aspnetcore-9.0

[rcj1]

Have you tried visualizing the "Microsoft.AspNetCore.Hosting" provider on a .NET web app? That shows an example of metrics with quite a few dimensions. I'm guessing this extra indent is a tradeoff between making the headers clearer when there are fewer dimensions vs. taking more horizontal space for cases with large numbers of dimensions. As long as the high dimension cases still look OK then tab is great. If high dimension cases don't look good any more than we might want to consider other options like smaller spacing or using "-----" to underline column headers instead.

https://learn.microsoft.com/en-us/aspnet/core/log-mon/metrics/metrics?view=aspnetcore-9.0

So in this case we have a table with headers lined up horizontally. It doesn't look truncated with the added indentation. On the other hand, in such a table one would expect the values to be left-aligned, which they are not. If the header name were short this could be an issue.

[rcj1]

I will see if it looks better with an underline.

[rcj1]

Ok I think it looks better with the underline especially in the web test. @noahfalk

[noahfalk]

Agreed, the underline looks better to me as well. As a small tweak, I think it might help visually separate the columns if you put a space in the underline in between the columns:

http.request.method http.request.status_code http.route
------------------- ------------------------ ----------
GET                 200                      /
GET                 200                      /
GET                 200                      /

[rcj1]

Yes this looks good to me: