Add insert_all

[ruslandoga]

This PR adds a helper NIF that can be used to bulk-insert "unlimited" number of rows.

Should be enough to clоse https://github.com/elixir-sqlite/exqlite/issues/129 once it gets into ecto_sqlite3

Regarding performance: XQLite uses this approach in insert_all benchmark in https://github.com/ruslandoga/elixir-sqlite-bench

[warmwaffles]

This looks good.

[warmwaffles]

I do not like how often the windows test flaps.

[warmwaffles]

Ugh

c_src\sqlite3_nif.c(703): error C2057: expected constant expression
c_src\sqlite3_nif.c(703): error C2466: cannot allocate an array of constant size 0
c_src\sqlite3_nif.c(703): error C2133: 'types_array': unknown size