Initial work on a tables lib

Incomplete lib intended to offer tables for all cryptographic libraries 
expecting them. Right now, it creates the tables at runtime. While that 
would still offer improvements, ideally large tables are built at 
compile time and simply entered into memory at runtime.

My best idea for that was a linked list in the binary itself, where this 
app (at first call), reads a table stored to a section of data, then 
grabs the next reference to one and continues reading. The main issue 
with this idea, besides not yet researching how to encode data into the 
binary, was the fact the same table would be saved to disk multiple 
times under this simplistic model. An O(n) iteration when writing to the 
bin could potentially solve that.

Related https://github.com/serai-dex/serai/issues/41.

Cargo.toml

@@ -3,6 +3,7 @@ members = [
   "crypto/transcript",
 
   "crypto/dalek-ff-group",
+  "crypto/tables",
   "crypto/multiexp",
 
   "crypto/dleq",