Add dropdown versions of blocks for artist toolbox
[Finishes #76303890] Updated 4-5 Artist (4,5,10) levels to use non-deletable and non-editable starting blocks.
Merge branch 'finished' of github.com:code-dot-org/dashboard into finished
Merge pull request #1142 from code-dot-org/add_number_dropdown_blocks_to_toolbox

Add dropdown versions of blocks for artist toolbox
Add dropdown versions of maze repeat blocks
Merge pull request #1143 from code-dot-org/maze_toolbox_number_dropdowns

Add dropdown versions of maze repeat blocks
Update level order [finishes #76101598]
Merge pull request #1144 from code-dot-org/finished

Deploy to delivered