Improve `tt binaries list`

tt binaries list prints versions based on bin_dir only. It might be confusing while using it to print tarantool versions because include files might be missing.

I suggest to add an additional check for tarantool include files presence, and either don't print versions with missing files or print an error.

f.terekhin@f-terekhin tt % ls -al binaries
total 90480
drwxr-xr-x   6 f.terekhin  staff       192 Jun 20 18:35 .
drwxr-xr-x  41 f.terekhin  staff      1312 Jun 20 18:13 ..
-rw-r--r--   1 f.terekhin  staff         0 Jun 20 18:35 tarantool_2.3.0
lrwxr-xr-x   1 f.terekhin  staff         9 Jun 20 14:00 tt -> tt_v2.3.1
-rwxr-xr-x   1 f.terekhin  staff  23159088 Jun 20 13:40 tt_v2.3.0
-rwxr-xr-x   1 f.terekhin  staff  23159088 Jun 20 13:59 tt_v2.3.1
f.terekhin@f-terekhin tt % ls -al include/include 
total 0
drwxr-xr-x   5 f.terekhin  staff  160 May 29 12:47 .
drwxr-x---   3 f.terekhin  staff   96 Mar 13 14:29 ..
f.terekhin@f-terekhin tt % ./tt binaries list    
List of installed binaries:
   • tt:                      
	2.3.1 [active]
	2.3.0
   • tarantool:               
	2.3.0

Start at the tt binaries list command and trace how entries from bin_dir become displayed versions. Check how Tarantool include files are represented, then define completion as avoiding misleading versions with missing files or reporting a clear error. Add coverage for the shown empty-include-files case if the command's tests are found.