output for long waiting conan-list commands

[memsharded]

Changelog: Feature: Display progress for long conan list commands.
Docs: Omit

Will display something like this, displaying something every 5 seconds:

(conan2_36) λ conan list z*#*:* -r=conancenter
Found 84 pkg/version recipes matching z* in conancenter
Listing revisions of z3/4.11.2 in conancenter (3/84)
Listing binaries of zbar/0.10#3c8869d4c554b578e2b67afeb1813028 in conancenter (6/8)
Listing revisions of zbar/0.23.92 in conancenter (7/84)
Listing binaries of zbar/0.23.92#19b32916172bc37203cadf4b85f94735 in conancenter (3/5)
Listing binaries of zbar/0.23.92#17419480121dda01c64e7bf8b2f0d086 in conancenter (4/5)
Listing revisions of zeromq/4.3.2 in conancenter (8/84)
Listing binaries of zeromq/4.3.2#9b754f566bf3108bba0deda1bcba3d3f in conancenter (4/15)
Listing binaries of zeromq/4.3.2#4ecc885cfac2e1da8da551dfc36c2712 in conancenter (6/15)