Clean up layout-files

- Change text to symbols
- Remove unused button-definitions

This makes these layout-files easier to understand and edit.

Part-of: <https://gitlab.gnome.org/World/Phosh/squeekboard/-/merge_requests/629>

data/keyboards/fr+bepo_wide.yaml

@@ -16,11 +16,11 @@ views:
         - "B É P O W V D L J Z"
         - "A U I E C T S R N M"
         - "Shift_L   Y X K Q G H F -  BackSpace"
-        - "show_numbers preferences         space  colon   show_eschars Return"
+        - "show_numbers preferences         space  :   show_eschars Return"
     numbers:
         - "1 2 3 4 5 6 7 8 9 0"
         - "@ # € % & - _ + ( )"
-        - "show_symbols   , \" ' colon ; ! ?  BackSpace"
+        - "show_symbols   , \" ' : ; ! ?  BackSpace"
         - "show_letters preferences         space        show_eschars Return"
     symbols:
         - "~ ` | · √ π τ ÷ × ¶"
@@ -83,7 +83,3 @@ buttons:
         outline: "wide"
         icon: "key-enter"
         keysym: "Return"
-    colon:
-        text: ":"
-    "\"":
-        keysym: "quotedbl"