Show error message for the failed monitor runs in dashboard

[ftianli-amzn]

Issue #, if available:

Description of changes:

Currently if there is an error occurs in monitor runs, it just shown as Error, the error message is missing. This PR will make it shown as Error: <error message>.

• In Dashboard
  

• In Monitor Detail page
  

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[ftianli-amzn]

yarn test:jest

Test Suites: 6 skipped, 78 passed, 78 of 84 total
Tests:       20 skipped, 366 passed, 386 total
Snapshots:   127 passed, 127 total
Time:        35.461s
Ran all test suites.
✨  Done in 36.74s.

[dbbaughe]

What is the longest length error that will be shown? How will that look on the UI without being truncated in a narrow column?

[ftianli-amzn]

Test Suites: 6 skipped, 78 passed, 78 of 84 total
Tests:       20 skipped, 366 passed, 386 total
Snapshots:   127 passed, 127 total
Time:        42.712s
Ran all test suites.
✨  Done in 43.88s.

[ftianli-amzn]

What is the longest length error that will be shown? How will that look on the UI without being truncated in a narrow column?

Hi, finally we decided not to truncate the text in the table. The error messages will be refined and optimized in the backend to be more user friendly, while the original long messages are reserved as well.