Fix lint errors in multiple files (#2192)

* fix (plugins): enable interpretation of backslash escapes in colors
* fix (lint): disable SC2317 in install.sh
* fix (lint): SC2086 in agnoster theme
* fix (lint): remove exit from install.sh as it is already implemented in the calling function

plugins/available/colors.plugin.bash

@@ -8,13 +8,13 @@ function __() {
 function __make_ansi() {
 	next=$1
 	shift
-	echo "\[\e[$("__$next" "$@")m\]"
+	echo -e "\[\e[$("__$next" "$@")m\]"
 }
 
 function __make_echo() {
 	next=$1
 	shift
-	echo "\033[$("__$next" "$@")m"
+	echo -e "\033[$("__$next" "$@")m"
 }
 
 function __reset() {