feat: Add Get Random UUID, Get Epoch Time, and Add Slashes workflows

[hahwul]

In security testing, it’s often necessary to generate the current timestamp or create a random UUID. These techniques are also valuable for tasks like cache-busting. I've applied this approach in a workflow and am now sharing it with the community.

Example for Get Random UUID

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Please ensure your pull request adheres to the following guidelines:

• [x] Follow the same folder structure as other workflows (see template).
• [x] Has a proper author name and workflow description.
• [x] If using compiled code in JS Nodes, provide the source code for each. -> not used
• [x] If using a 3rd party library, include its license as a comment in the source code. -> not used

Thanks for contributing!