Fixed Percent delimiter for hex encoding

[beneri]

Related to issue #464

Percent (%) should be prepended, similar to "\x" and "0x".

[C85297]

Issue replicated: https://gchq.github.io/CyberChef/#recipe=To_Hex('Percent',0)&input=YWJjZGVmZw
Output is: 61%62%63%64%65%66%67
Should be: %61%62%63%64%65%66%67

[C85297]

This looks good to me @beneri , however it would benefit from some tests. Would you be able to create a test file tests/operations/tests/ToHex.mjs (you can use any of the other files in that directory as a template) to check that ToHex correctly performs the new behaviour as expected?

[beneri]

Good point about tests! I've added a new test for the percent delimiter.
There were already some tests for ToHex in Hex.mjs, I assume it is fine to put it there. Let me know otherwise.

[C85297]

Thank you for your contribution @beneri !