- Added NadekoBot.Generators projects which will contain source generators

- Implemented initial version of the response strings source generator
  - Creates a class with property names equivalent to key names in responses.en-US.json
  - Each Property has struct type (with generic type parameters matching the number of string format placeholders) for type safe GetText implementation
  - Struct types are readonly refs as they should be ephermal, and only used to pass string keys to GetText

src/NadekoBot/data/strings/responses/responses.en-US.json

@@ -323,7 +323,7 @@
   "waifu_reset_fail": "Failed resetting waifu stats. Make sure you have enough currency.",
   "waifu_reset_confirm": "This will reset your waifu stats",
   "waifu_reset_price": "Price: {0}",
-  "8ball": "8ball",
+  "_8ball": "8ball",
   "acrophobia": "Acrophobia",
   "acro_ended_no_sub": "Game ended with no submissions.",
   "acro_no_votes_cast": "No votes cast. Game ended with no winner.",
@@ -508,7 +508,7 @@
   "cost": "Cost",
   "date": "Date",
   "word": "Word",
-  "class": "Class",
+  "_class": "Class",
   "definition": "Definition",
   "example": "Example",
   "dropped": "Dropped",
@@ -629,10 +629,10 @@
   "repeater_removed": "Repeater #{0} Removed",
   "repeater_exceed_limit": "You cannot have more than {0} repeaters per server.",
   "repeater_remove_fail": "Failed removing repeater on that index. Either you've specified invalid index, or repeater was in executing state at that time, in which case, try again in a few seconds.",
-  "interval:": "Interval:",
-  "executes_in:": "Executes in:",
-  "message:": "Message:",
-  "no_redundant:": "Won't post duplicate message.",
+  "interval_colon": "Interval:",
+  "executes_in_colon": "Executes in:",
+  "message_colon": "Message:",
+  "no_redundant": "Won't post duplicate message.",
   "name": "Name",
   "nickname": "Nickname",
   "nobody_playing_game": "Nobody is playing that game.",