use predicate for XCUITest to improve performance

[KazuCocoa]

https://github.com/appium/appium/blob/master/docs/en/writing-running-appium/ios_predicate.md

• text/s()
• button/s()
• and so on...

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I guess this improve some method's performance.

[KazuCocoa]

replace find_eles_by_attr_include '', '', value with:

text = "sample"
find_elements(:predicate, "name contains[c] '#{text}' || label contains[c] '#{text}' || value contains[c] '#{text}'")

replace find_eles_by_attr '', '', value with:

text = "sample"
find_elements(:predicate, "name == '#{text}' || label == '#{text}' || value == '#{text}'")

[KazuCocoa]

find predicate with type => add a test for predicate #499

[KazuCocoa]

according to the following specs and webdriveragent's wiki, visible == 1 should work...
https://github.com/appium/appium-xcuitest-driver/blob/d68925fc5d9d1bb86ffc662fcc691ad4371cd4d2/test/functional/basic/find-e2e-specs.js