Fix accessibility for ultimate trial SVG

What does this MR do and why?

Implements accessibility suggestions from &11510 (closed)

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. In line 156 of gitlab/app/assets/javascripts/super_sidebar/components/super_sidebar.vue, change <div v-if="showTrialStatusWidget" to <div v-if="sidebarData.is_logged_in".

2. Changes lines 19–29 of gitlab/ee/app/assets/javascripts/contextual_sidebar/components/trial_status_widget.vue to:

    trialDaysUsed: { default: 5 },
    trialDuration: { default: 30 },
    navIconImagePath: {
      default:
        '/assets/illustrations/golden_tanuki-a88ad492b973a0ea6be2316b12aeb3a76ee4e926b3b217dc26d01a57033c9948.svg',
    },
    percentageComplete: { default: 10 },
    // eslint-disable-next-line @gitlab/require-i18n-strings
    planName: { default: 'Ultimate Trial' },
    plansHref: { default: '/asdf' },

3. Inspect the accessibility tree.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #426359 (closed)