sideload-createuidef.sh launched URL is incorrect

### Issue Details
Running sideload-createuidef.sh on the demo results in the script opening the wrong URL.

Enabling -x in the bash script I see the correct URL:
`+ echo 'https://portal.azure.com/#blade/Microsoft_Azure_Compute/CreateMultiVmWizardBlade/internal_bladeCallId/anything/internal_bladeCallerParams/{"providerConfig":{"createUiDefinition":"[xxx]"}}'
`
Copying that URL directly into the web browser works fine.

However the resulting python command has the wrong encoding:
`python -mwebbrowser 'https://portal.azure.com/#blade/Microsoft_Azure_Compute/CreateMultiVmWizardBlade/internal_bladeCallId/anything/internal_bladeCallerParams/{"providerConfig":{"createUiDefinition":"xxx"}}'
`

The resulting URL in the web browser starts with "https://portal.azure.com/%23blade" instead of "https://portal.azure.com/#blade"

Test environment:
macOS Catalina 10.15.6
Python 2.7.16 or Python 3.8.10 (fails with either one)

### Repro steps (*if necessary, delete otherwise*)
1. cd demos/100-marketplace-sample
2. ../../sideload-createuidef.sh -f createUiDefinition.json -l WestUS2 -a . my-offer

Start with sideload-createuidef.sh and reproduce the command from the issue in demos/100-marketplace-sample. Compare the URL echoed by the script with the URL passed to python -mwebbrowser, then verify that the launched URL preserves the #blade fragment instead of encoding it as %23.

Written by the indexing model from the issue text.