treat bigint as string in msnodesqlv8 driver

[dhensby]

What this does:

BigInts should be treated as strings to ensure no precision loss

Related issues:

Attempt to fix #1385

Pre/Post merge checklist:

• [x] Update change log

[dhensby]

Well, interestingly, the tedious driver does not allow strings to be used for bigints and instead they must be set to varchars...

[blitzmann]

Would there be an argument for using JS's BitInt type instead of a string? https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt

mssql doesn't support Node versions < 10 according to changelog, and it's been around since 10.4

[dhensby]

Yep, definitely, but it's more about the underlying drivers than about this library. If they support either strings and/or BigInt, then we can use them.

[blitzmann]

Ah that makes sense

[dhensby]

Well, interestingly, the tedious driver does not allow strings to be used for bigints and instead they must be set to varchars...

So this is the problem we have getting this merged, the tedious driver is the blocker