Set max width for md editor tooltip, Add untitled key, Add logo alt text to metadata

[IshavSohal]

Related Item(s)

#452
#443
#438

Changes

• Set a max width of 90px for tooltips within the v-md-editor component, so that a horizontal scrollbar doesn't appear when the tooltip exits the screen
• Add the chapters.untitled key into lang.csv, so that the appropriate text appears in the ToC for slides without a title
• Include the logo alt text within the metadata upon creating a new object

Testing

Steps (#452):

1. Open a text panel
2. Decrease the screen width
3. Hover over the buttons on the right side of the editor
4. Observe that the horizontal bar doesn't appear

Steps (#443):

1. Remove the titles from one/more slide
2. Switch the ToC to horizontal
3. Open the preview
4. Observe that the title of each slide without a title (within the ToC) is 'Untitled Slide'
5. Switch to French and observe the corresponding French text in the ToC

Steps (#438):

1. Create a new product
2. Upload a logo and set the alt text
3. Click Next to proceed to the main editor page
4. Click Edit Product Metadata
5. The alt text should be visible

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This change is 

[github-actions]

Your demo site is ready! 🚀 Visit it here: https://ramp4-pcar4.github.io/storylines-editor/issue-452