update tests with additional tests and snapshots using v4

[adonesky1]

Adds tests for encoded data types of hexadecimal strings that convert to numbers equal to or greater than Javascript's MAX_SAFE_INTEGER. The following additional test cases are added to each encoded field "type":

1. 0x1fffffffffffff - The hex string equal to Number.MAX_SAFE_INTEGER, which contains an even number (16) of characters
2. 0x1fffffffffffff1 a hex string that contains an odd number of characters (17) and is greater than Number.MAX_SAFE_INTEGER.
3. 0x101 a hex string that contains an odd number of characters and is less than Number.MAX_SAFE_INTEGER

We test both even and odd length hex values because Node's Buffer.from() method does not buffer hex numbers correctly
so we must conditionally prepend hexstrings with a zero before buffering them depending on whether the string contains an
even or odd number of characters.

The added snapshots were taken by adding the additional test values to 219511e, the commit of the last release before v5 caused regressions to encoding of buffered hex strings.

You can manually test this by adding the new tests to a previous release (4.0.0 or 4.0.1), update the snapshots (yarn jest -u). Copy the updated snapshot file to this branch and run the tests to ensure that v5 matches the expected output for encoding these values.