fix(searchbar): setting dir on ion-searchbar to enable rtl mode now supported

[sean-perkins]

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Build (npm run build) was run locally and any changes were pushed
• Lint (npm run lint) has passed locally and any fixes were made for failures

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

ion-searchbar only supports RTL when the direction is set at the document level.

Issue Number: Tech Debt

What is the new behavior?

• ion-searchbar will respect dir specified on the host element (overrides the document value)
• ion-searchbar uses the isRTL utility

Does this introduce a breaking change?

• Yes
• No

Other information