Fix #10893 Making sure scripts from extensions are not cached

[MV88]

Description

This way intex.js is appended by a random param making sure that script will not be cached.
I just noticed that removeExtensions seems not be triggered when removing the installed extension. can you double check is the case?

Please check if the PR fulfills these requirements

• The commit message follows our guidelines: https://github.com/geosolutions-it/MapStore2/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (check one with "x", remove the others)

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

Issue

What is the current behavior?

Fix #10893

What is the new behavior?

index.js of the extensions will not be cached

Breaking change

Does this PR introduce a breaking change? (check one with "x", remove the other)

• Yes, and I documented them in migration notes
• No

Other useful information

to test this locally when targeting dev env

 '/extensions/': {
            target: MAPSTORE_BACKEND_URL,
            secure: false,
            headers: {
                host: domain
            }
        },
        '/configs/pluginsConfig.json': {
            target: MAPSTORE_BACKEND_URL,
            secure: false,
            headers: {
                host: domain
            }
        }