More copy-able result for `@benchmark`

Sometimes users want to copy the result for comparison where @btime gives too little information but the current @benchmark is unfriendly for that.

One proposal is to change now:

julia> @benchmark sin(3)
BechmarkTools.Trial: 10000 samples with 1000 evaluations.
 Range (min … max):  1.301 ns … 15.216 ns  ┊ GC (min … max): 0.00% … 0.00%
 Time  (median):     1.384 ns              ┊ GC (median):    0.00%
 Time  (mean ± σ):   1.456 ns ±  0.294 ns  ┊ GC (mean ± σ):  0.00% ± 0.00%

        █     ▅                                           ▂   
  ▅▃▂▁▁▃█▆▃▂▂▄█▄▃▂▁▂▄▃▂▂▁▁▃▆▃▂▁▂▁▂▅▃▂▁▁▁▂▄▄▂▂▂▁▁▂▄▃▃▂▁▁▁▁▅█▄ ▃
  1.3 ns         Histogram: frequency by time        1.65 ns <

 Memory estimate: 0 bytes, allocs estimate: 0.

to

julia> @benchmark sin(3)
BechmarkTools.Trial: 10000 samples with 1000 evaluations.
 Range (min … max):  1.301 ns … 15.216 ns 
 Time  (median):     1.384 ns              
 Time  (mean ± σ):   1.456 ns ±  0.294 ns
 -----------------------------------------
 GC (min … max): 0.00% … 0.00%
 GC (median):    0.00%
 GC (mean ± σ):  0.00% ± 0.00%

        █     ▅                                           ▂   
  ▅▃▂▁▁▃█▆▃▂▂▄█▄▃▂▁▂▄▃▂▂▁▁▃▆▃▂▁▂▁▂▅▃▂▁▁▁▂▄▄▂▂▂▁▁▂▄▃▃▂▁▁▁▁▅█▄ ▃
  1.3 ns         Histogram: frequency by time        1.65 ns <

 Memory estimate: 0 bytes, allocs estimate: 0.

so that people can copy the first 3-4 lines without sending really long, wrapped lines.

Besides I think it's much easier to navigate vertically anyway

Start by locating the @benchmark output and formatting entry point, then inspect any existing output-related tests. Compare the current layout with the proposed separated timing and GC sections. Done means the first lines are vertically arranged and copyable without long wrapped lines, while the histogram and other output remain available.