perf(various): don't use lazy-loaded icon names in components

[amandaejohnston]

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?

Issue Number: N/A (tech debt issue)

Many components use lazy-loaded ionicon names, which requires us to front-load the imports in React and Vue. This leads to a larger bundle size than necessary if you don't use all the related components, and is difficult to maintain since you have to remember to edit the front-load.

What is the new behavior?

• Icons are imported as raw SVG data directly in the component instead.
• Icon front-loading in React and Vue removed.
• Docs updated in a few places to not explicitly list the icon names as strings.

Does this introduce a breaking change?

• Yes
• No

Other information

[danleedham]

Unsure if anyone else has found this adds an additional error when operating with a stricter Content Security Policy? Not the end of the world, but wasn't expecting during a refactoring update. If so, adding data: to the CSP removes the errors. Not entirely related but did find this ionic-team/ionicons#1025