[skip changelog][skip ci] Correct lib name specification re: leading/trailing space

[per1234]

Please check if the PR fulfills these requirements

• The PR has no duplicates (please search among the Pull Requests before creating one)
• The PR follows our contributing guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

• What kind of change does this PR introduce?

Remove incorrect prohibition on leading or trailing spaces in the library.properties name field.

• What is the current behavior?

The library specification includes an unnecessary prohibition against leading or trailing spaces in the library.properties name field.

Leading and trailing space is correctly trimmed on all fields of library.properties, including name.

The unnecessary extra verbosity in the name specification may cause people to miss the other important restrictions.

• What is the new behavior?

The name specification only contains the true requirements.

• Does this PR introduce a breaking change?

No.