better support for boolean and lua tables

[kkharji]

Currently sql.nvim uses the following for interoping lua boolean to 0/1.

-- lua/sql.lua
local booleansql = function(value)
 if type(value) == "boolean" then
   value = (value == true) and 1 or 0
 end
 return value
end

However there are no support for interop 0/1 back to lua boolean. This aspect
should be handled in stmt module with the above code removed from sql:eval.

[kkharji]

sql.insert doesn't seem to interop boolean values.