[BugFix] calling pad with immutable sequence

[SamAdamDay]

Description

Allow functional.pad to take a tuple for pad_size.

Motivation and Context

I recently tried to use pad with a tuple for pad_size, but it didn't work as expected.

Close #1074

• I have raised an issue to propose this change (required for new features and bug fixes)

Types of changes

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• Bug fix (non-breaking change which fixes an issue)

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• I have read the CONTRIBUTION guide (required)
• My change requires a change to the documentation.
• I have updated the tests accordingly (required for a bug fix or a new feature).
• I have updated the documentation accordingly.

[SamAdamDay]

One meta-question: I raised an issue because the PR template told me to, but in future should I just make a PR for such a minor change?

[vmoens]

LGTM thanks!

[vmoens]

One meta-question: I raised an issue because the PR template told me to, but in future should I just make a PR for such a minor change?

Yep you can definitely do that!
If the work is taking you more than an hour it's probably worth raising an issue firt