BHV-3181: Add method for determining RTL mode based on first character of string content.

Issue
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We have multiple types of controls which need to determine RTL mode. We also need to ignore LTR numbers and punctuation, that comprise the first character, from causing the content to be classified as LTR.

Fix
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The previous method located in `Marquee` has been moved to `Control` to be available as a control-level method. We now use a regex to check for the occurrence of any RTL character, whereupon we classify the contents as being RTL.

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>