Fix broken reference to fail() after jest-upgrade

[haydenbaker]

Description of changes:

Jest versions >= 27 replace jest-jasmine2 with jest-circus, which does not have an implementation for the fail() method, but still has the method stub defined in the Jest type-defs. This change implements the fail() method in protocol test suites, and adjusts the thrown message to actually state the error, instead of just err.

For more information, see DefinitelyTyped maintainer discussion

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Testing
Run the protocol test suite after making changes and running the codegen

Before changes:

  ● Ec2QueryDateTimeWithNegativeOffset:Response

    ReferenceError: fail is not defined

      184 |     r = await client.send(command);
      185 |   } catch (err) {
    > 186 |     fail("Expected a valid response to be returned, got err.");
          |     ^
      187 |     return;
      188 |   }
      189 |   expect(r["$metadata"].httpStatusCode).toBe(200);

      at test/functional/ec2query.spec.ts:186:5
          at Generator.throw (<anonymous>)
      at rejected (../../node_modules/tslib/tslib.js:115:69)

After changes:

  ● Ec2QueryDateTimeWithNegativeOffset:Response

    Expected a valid response to be returned, got err:

    TypeError: Invalid RFC-3339 date-time value

      162 |  */
      163 | function fail(error?: any): never {
    > 164 |   throw new Error(error);
          |         ^
      165 | }
      166 |
      167 | /**

      at fail (test/functional/ec2query.spec.ts:164:9)
      at test/functional/ec2query.spec.ts:194:5
          at Generator.throw (<anonymous>)
      at rejected (../../node_modules/tslib/tslib.js:115:69)