Move the bash integration script into its own dir

This matches the other shells and might be useful someday
if bash ever gets a way for the invoking process to inject code
into it.

Also use KITTY_INSTALLATION_DIR when loading the bash integration code.

shell-integration/bash/kitty.bash

@@ -0,0 +1,66 @@
+#!/bin/bash
+
+_ksi_main() {
+    if [[ $- != *i* ]] ; then return; fi  # check in interactive mode
+    if [[ -z "$KITTY_SHELL_INTEGRATION" ]]; then return; fi
+    declare -A _ksi_prompt=( [cursor]='y' [title]='y' [mark]='y' [complete]='y' )
+    set -f
+    for i in ${KITTY_SHELL_INTEGRATION}; do
+        set +f
+        if [[ "$i" == "no-cursor" ]]; then _ksi_prompt[cursor]='n'; fi
+        if [[ "$i" == "no-title" ]]; then _ksi_prompt[title]='n'; fi
+        if [[ "$i" == "no-prompt-mark" ]]; then _ksi_prompt[mark]='n'; fi
+        if [[ "$i" == "no-complete" ]]; then _ksi_prompt[complete]='n'; fi
+    done
+    set +f
+
+    unset KITTY_SHELL_INTEGRATION
+
+    _ksi_debug_print() {
+        # print a line to STDOUT of parent kitty process
+        local b=$(printf "%s\n" "$1" | base64 | tr -d \\n)
+        printf "\eP@kitty-print|%s\e\\" "$b" 
+        # "
+    }
+
+    if [[ "${_ksi_prompt[cursor]}" == "y" ]]; then 
+        PS1="\[\e[5 q\]$PS1"  # blinking bar cursor
+        PS0="\[\e[1 q\]$PS0"  # blinking block cursor
+    fi
+
+    if [[ "${_ksi_prompt[title]}" == "y" ]]; then 
+        # see https://www.gnu.org/software/bash/manual/html_node/Controlling-the-Prompt.html#Controlling-the-Prompt
+        PS1="\[\e]2;\w\a\]$PS1"
+        if [[ "$HISTCONTROL" == *"ignoreboth"* ]] || [[ "$HISTCONTROL" == *"ignorespace"* ]]; then
+            _ksi_debug_print "ignoreboth or ignorespace present in bash HISTCONTROL setting, showing running command in window title will not be robust"
+        fi
+        local orig_ps0="$PS0"
+        PS0='$(printf "\e]2;%s\a" "$(HISTTIMEFORMAT= history 1 | sed -e "s/^[ ]*[0-9]*[ ]*//")")'
+        PS0+="$orig_ps0"
+    fi
+
+    if [[ "${_ksi_prompt[mark]}" == "y" ]]; then 
+        # bash does not redraw the leading lines in a multiline prompt so
+        # mark them as secondary prompts
+        local secondary_prompt="\n\[\e]133;A;k=s\a\]"
+        PS1=${PS1//"\n"/"$secondary_prompt"}
+        PS1="\[\e]133;A\a\]$PS1"
+        PS2="\[\e]133;A;k=s\a\]$PS2"
+        PS0="\[\e]133;C\a\]$PS0"
+    fi
+
+    if [[ "${_ksi_prompt[complete]}" == "y" ]]; then 
+        _ksi_completions() {
+            local src
+            local limit
+            # Send all words up to the word the cursor is currently on
+            let limit=1+$COMP_CWORD
+            src=$(printf "%s\n" "${COMP_WORDS[@]: 0:$limit}" | kitty +complete bash)
+            if [[ $? == 0 ]]; then
+                eval ${src}
+            fi
+        }
+        complete -o nospace -F _ksi_completions kitty
+    fi
+}
+_ksi_main