Numbers are not correctly detected resulting in a NumberFormatException

[JanHolger]

Describe the Bug
We detected numbers based on certain characters but we don't validate that they actually match the syntax of a number. Instead of throwing a proper exception we hand the value to parseLong/parseDouble resulting in a NumberFormatException being thrown

To Reproduce
Steps to reproduce the behavior:

AbstractElement.fromJson("--")

Expected behavior
It should fail fast and throw a proper exception

Screenshots / Logs
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Environment Information:

• Java Language Level 8
• Version 1.0.6