Change validation of environment name to not include dot

[prakarsh-dt]

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• I've searched in the docs and FAQ for my answer
• I've included steps to reproduce the bug.

Describe the bug

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To Reproduce

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1. User goes to Create an application (to save space or whatever)
2. User selects clone option
3. Configmap in environment override is not cloned

Expected behavior

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Current behavior

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