feat: add string based title api to card

[ugur-vaadin]

Description

Adds the following String based title API to the Card component:

• String getTitleAsText()
• void setTitle(String title)
• void setTitle(String title, Integer titleHeadingLevel)
• void setTitleHeadingLevel(Integer titleHeadingLevel)

Depends on the related web component PR and TestBench API PR.

Fixes #7212

Type of change

• [ ] Bugfix
• [x] Feature

Checklist

• [x] I have read the contribution guide: https://vaadin.com/docs/latest/contributing/overview
• [x] I have added a description following the guideline.
• [x] The issue is created in the corresponding repository and I have referenced it.
• [x] I have added tests to ensure my change is effective and works as intended.
• [x] New and existing tests are passing locally with my change.
• [x] I have performed self-review and corrected misspellings.
• [x] Enhancement / new feature was discussed in a corresponding GitHub issue and Acceptance Criteria were created.

[sonarqubecloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[vaadin-bot]

This ticket/PR has been released with Vaadin 24.7.2.