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)

Scratch3-Dev-Tools/inject3.js

Line 2002 in 4b792e7

options.sort((a, b) => a.desc.localeCompare(b.desc));

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.

Scratch3-Dev-Tools/inject3.js

Line 2029 in 4b792e7

let desc;

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