CKO - Better card token handling

[Fifciu]

Current behavior

We are storing card/instrument token inside localStorage.

Expected behavior

We should store it in sessionStorage and remove it if someone leaves checkout.

Version of Vue Storefront

• Vue Storefront
• Vue Storefront Next

Can you handle fixing this bug by yourself?

• YES
• NO

Which Release Cycle state this refers to? Info for developer. (doesn't apply to Next)

Pick one option.

• This is a bug report for test version on https://test.storefrontcloud.io - In this case Developer should create branch from develop branch and create Pull Request 2. Feature / Improvement back to develop.
• This is a bug report for current Release Candidate version on https://next.storefrontcloud.io - In this case Developer should create branch from release branch and create Pull Request 3. Stabilisation fix back to release.
• This is a bug report for current Stable version on https://demo.storefrontcloud.io and should be placed in next stable version hotfix - In this case Developer should create branch from hotfix or master branch and create Pull Request 4. Hotfix back to hotfix.

Todo

• localStorage -> sessionStorage
• remove stored token in onUnmounted