Insert blocks when selecting many cells

[zbeyens]

https://user-images.githubusercontent.com/19695832/184238907-4bfb2b08-420f-42bc-8ad3-b7655c084aa7.mp4

Given

• Selecting table cells

        <editor>
          <htable>
            <htr>
              <htd>
                <anchor />
                11
              </htd>
              <htd>
                12
                <focus />
              </htd>
            </htr>
          </htable>
        </editor>

When

• inserting many blocks (not tables)

        <fragment>
          <hp>o11a</hp>
          <hp>o11b</hp>
        </fragment>

Then

• should keep the rows/cells
• should replace the cells by a new cell with the same blocks in each selected cell

        <editor>
          <htable>
            <htr>
              <htd>
                <hp>o11a</hp>
                <hp>o11b</hp>
              </htd>
              <htd>
                <hp>o11a</hp>
                <hp>o11b</hp>
              </htd>
            </htr>
          </htable>
        </editor>