Feature Request: Show byte 00~1f and 7f in UnixP form in text area

[cheny0y0]

That is:	Byte	Show
00	^@
01	^A
02	^B
03	^C
04	^D
05	^E
06	^F
07	^G
08	^H
09	^I
0a	^J
0b	^K
0c	^L
0d	^M
0e	^N
0f	^O
10	^P
11	^Q
12	^R
13	^S
14	^T
15	^U
16	^V
17	^W
18	^X
19	^Y
1a	^Z
1b	^[
1c	^\
1d	^]
1e	^^
1f	^_
7f	^?

Use the second character to show it in a different color in text area.

[sharkdp]

I think this is out of scope for hexyl, unfortunately. It doesn't really fit with its current output width, for example. See also: #6