A procedure with no labels breaks the floating input box

[SheepTester]

An error is thrown when trying to sort the block names alphabetically:

chrome-extension://phacniajokfchdcamjhonkbhlcipplno/inject3.js:1631 TypeError: Cannot read property 'localeCompare' of undefined
    at chrome-extension://phacniajokfchdcamjhonkbhlcipplno/inject3.js:1999
    at Array.sort (<anonymous>)
    at buildFloatingFilterList (chrome-extension://phacniajokfchdcamjhonkbhlcipplno/inject3.js:1999)
    at middleClickWorkspace (chrome-extension://phacniajokfchdcamjhonkbhlcipplno/inject3.js:1870)
    at middleClick (chrome-extension://phacniajokfchdcamjhonkbhlcipplno/inject3.js:1887)
    at HTMLDocument.eventMouseDown (chrome-extension://phacniajokfchdcamjhonkbhlcipplno/inject3.js:1629)

https://github.com/griffpatch/Scratch3-Dev-Tools/blob/4b792e7dcac4154e6f7e4b99c5888a5fe11e9e8c/inject3.js#L2002

This is because the custom block's desc property in options is undefined, so it can't call localeCompare on it. I think it's because in getBlockText, desc is uninitialized, and since there are no text fields on the custom block, desc never gets set to a string and remains undefined.

https://github.com/griffpatch/Scratch3-Dev-Tools/blob/4b792e7dcac4154e6f7e4b99c5888a5fe11e9e8c/inject3.js#L2029

Custom extensions that define blocks that are purely inputs also will break the floating input box, which is how this issue was initially encountered