Improve deform: linear interpolation for twist and average local airfoil normal #1217

Job	Run time
Julia 1.12 - ubuntu-latest - x64 - with code coverage	1m 58s
Julia 1.11 - ubuntu-latest - x64 - pull_request	1m 56s
Julia 1.12 - windows-latest - x64 - pull_request	1m 49s
Julia 1.11 - ubuntu-latest - x64 - with code coverage	1m 59s
Documentation	1m 58s
Julia 1.12 - macOS-latest - aarch64 - pull_request	2m 3s
Julia 1.12 - ubuntu-latest - x64 - pull_request	1m 56s
	13m 39s

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