[LANG-1282] Preserve non-breaking spaces in normalizeSpace

[glebchik228]

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Description

Fixes LANG-1282.

StringUtils.normalizeSpace currently replaces non-breaking spaces
(U+00A0) with regular ASCII spaces.

This is inconsistent with the method's use of Character.isWhitespace,
which does not consider U+00A0 to be whitespace.

This change:

• adds regression tests covering non-breaking spaces;
• preserves non-breaking spaces instead of converting them to regular spaces;
• updates the existing test expectation accordingly.