feat(ottl): Add a new ottl trim function that trims leading and trailing whitespace from a string

[rnishtala-sumo]

Description

A field test exists in an event, which contains the string " this is a test ".

I would like to be able to transform this using an ottl function trim, that I would define as trim(attribute["test"]), which would trim this down to "this is a test".

• Trim(" this is a test ") results in this is a test

Link to the issue - https://github.com/open-telemetry/opentelemetry-collector-contrib/issues/34100

[TylerHelmuth]

@rnishtala-sumo can you add to the description the issue this PR closes