Fix remaining SpotBugs UC_USELESS_CONDITION warnings

Addressed persistent SpotBugs warnings in core classes:
* CodenameOne/src/com/codename1/util/MathUtil.java: Removed redundant `if (ix >= 0x3ff00000)` check in `ieee754_pow` as it is logically implied by previous conditions.
* CodenameOne/src/com/codename1/ui/MenuBar.java: Removed redundant `COMMAND_BEHAVIOR_SIDE_NAVIGATION` check which was impossible in the given context.
* CodenameOne/src/com/codename1/impl/CodenameOneImplementation.java: Removed redundant `(c == 10)` check in `isWhitespace` as `\n` (10) was already checked.
* CodenameOne/src/com/codename1/ui/html/HTMLComponent.java, CSSParser.java, XMLParser.java, CSSEngine.java: Standardized whitespace checks to remove redundancy (`\n` vs 10) and ensured consistency.

These fixes clean up logic errors and redundant code flagged by strict static analysis.

Author: google-labs-jules[bot]

CodenameOne/src/com/codename1/impl/CodenameOneImplementation.java

@@ -3651,7 +3651,7 @@ public int getCharLocation(String source, int index) {
     }
 
     private boolean isWhitespace(char c) {
-        return c == ' ' || (c == '\n') || (c == '\t') || (c == 10) || (c == 13);
+        return c == ' ' || (c == '\n') || (c == '\t') || (c == 13);
     }
 
     /**

CodenameOne/src/com/codename1/ui/MenuBar.java

@@ -1055,8 +1055,7 @@ public void addCommand(Command cmd) {
                     return;
                 }
                 if (parent.getBackCommand() != cmd) {
-                    if ((behavior == Display.COMMAND_BEHAVIOR_BUTTON_BAR_TITLE_BACK ||
-                            behavior == Display.COMMAND_BEHAVIOR_SIDE_NAVIGATION)
+                    if ((behavior == Display.COMMAND_BEHAVIOR_BUTTON_BAR_TITLE_BACK)
                             && parent.getTitle() != null && parent.getTitle().length() > 0) {
                         synchronizeCommandsWithButtonsInBackbutton();
                         return;

CodenameOne/src/com/codename1/util/MathUtil.java

@@ -637,9 +637,7 @@ private static final double ieee754_pow(double x, double y) {
                 if (ix <= 0x3fefffff) {
                     return (hy < 0) ? huge * huge : tiny * tiny;
                 }
-                if (ix >= 0x3ff00000) {
-                    return (hy > 0) ? huge * huge : tiny * tiny;
-                }
+                return (hy > 0) ? huge * huge : tiny * tiny;
             }
             /* over/underflow if x is not close to one */
             if (ix < 0x3fefffff) {