feat(switch): Add density support for switch component.

[joyzhong]

Fixes #5124 and #5104

• Add mdc-switch-density, mdc-switch-ripple-size mixins
• Rename $mdc-switch-tap-target-size => $mdc-switch-ripple-size, to be consistent with e.g. checkbox

BREAKING CHANGE: Renames switch variables $mdc-switch-tap-target-size => $mdc-switch-ripple-size, removes $mdc-switch-tap-target-initial-position and $mdc-switch-native-control-width.

[mdc-web-bot]

🤖 Beep boop!

Screenshot test report 🚦

6 screenshots changed from develop on commit 72aa506:

• https://storage.googleapis.com/mdc-web-screenshot-tests/travis/2019/09/24/18_40_08_323/report/report.html?utm_source=github&utm_medium=pr_comment

Details

6 Removed:

• spec/mdc-list/classes/disabled-checkbox.html

• spec/mdc-list/classes/disabled-radio.html

[mdc-web-bot]

🤖 Beep boop!

Screenshot test report 🚦

3 screenshots changed from develop on commit 1831218:

• https://storage.googleapis.com/mdc-web-screenshot-tests/travis/2019/09/25/15_30_03_333/report/report.html?utm_source=github&utm_medium=pr_comment

Details

3 Added:

• spec/mdc-switch/mixins/density.html

[mdc-web-bot]

🤖 Beep boop!

Screenshot test report 🚦

3 screenshots changed from develop on commit b1fc610:

• https://storage.googleapis.com/mdc-web-screenshot-tests/travis/2019/09/25/16_00_48_018/report/report.html?utm_source=github&utm_medium=pr_comment

Details

3 Added:

• spec/mdc-switch/mixins/density.html

[abhiomkar]

LGTM!