CueGui, fix limit assignation bug

[KernAttila]

Link the Issue(s) this Pull Request is related to. When a limit has a space in its name, it is not possible to assign it to a layer in cueGui. Test:

• create a limit "Max 5 frames", submit a job with this limit.
• The layer displays the limit correctly
• Now edit the layer in cueGui (change minCores for instance)
• Save
• The limit disappear

Summarize your change. Fix: do not strip spaces in the UI The fail comes from str.isalnum() which returns False when a string contains a whitespace.

Fix: strip limit name when renaming (already done when creating a new one)

[linux-foundation-easycla[bot]]

The committers listed above are authorized under a signed CLA.

• :white_check_mark: login: KernAttila / name: Kern Attila GERMAIN (04e69671ae80f03046d9e07f268a2e99259c8266, 90b758159aafbcea75752dc474a719e52f3dfe61, b5ac7c751d2e2cb0b1d466d9e722be34c8f3bbec, a283661389a1ab2d705e8d4b6ea5341022ab2dee, 58b0bc3da8daabe674cd7948e1edb9cd657095f1, 15202f2021ef314e742e7f68bc1af8591c982a25)

[KernAttila]

/easycla

[KernAttila]

Sorry, got mixed up between my work and personnal account. I rebased the commits with the proper author.