Export cpad function

[djsegal]

for reference, this was started through the following discourse post:

• https://discourse.julialang.org/t/is-there-native-function-for-cpad-center-version-of-lpad-rpad/4045

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summarizing, cpad:

• is not exported
• doesn't work with symbols
• seems like it could be extracted w/ other string manipulations into their own package

[fredrikekre]

Deprecated in #23187 instead.

[amanica]

aah, I found cpad quite useful :'( . Is there a String utils package for this sort of thing or should I create it?