[Fix]: UInt160.TryParse when source has whitespaces

[nan01ab]

Description

According to

neo/src/Neo/UInt160.cs

Line 157 in e0edd98

if ((str.Length - startIndex) != Length * 2) return false;

UInt160.TryParse parses a hex-string with 40 chars.
But leading or trailing whitespace when byte.TryParse with NumberStyles.HexNumber, so
UInt160.TryParse(" 1 2 3 45 000000000000000000000000000000", out _) will return true.
It's weird and unexpected.

Fixes # (issue)

Type of change

• Optimization (the change is only an optimization)
• Style (the change is only a code style for better maintenance or standard purpose)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[AnnaShaleva]

An unexpected one.