Do not delete keymaterial before file

[mswintermeyer]

Before this PR

Two bugs exist in EncryptedFileSystem that could cause a KeyMaterial to be deleted before the file that it encrypts.

First, if rename returns false but the destination file still exists, we should never delete the destination's KeyMaterial. This could happen when trying to rename a file when the destination file already exists, though that means there's likely a bug with the code that called rename. It could also signify an edge case with the rename code itself, e.g. AzureNativeFileSystemStore#rename can succeed at renaming the file but still not fully succeed because of an error at the end of the file when calling AzureNativeFileSystemStore#safeDelete to try to delete the source file.

Second, delete should be the inverse of create. When we create a file, we create its KeyMaterial before the actual file. Thus, on delete, we should flip that order and delete the file before the KeyMaterial. Only if the file actually got deleted should we delete its KeyMaterial.

After this PR

==COMMIT_MSG== Fix some edge cases that could cause a KeyMaterial to be deleted before the file that it encrypts ==COMMIT_MSG==

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• [ ] Migration

Description Fix some edge cases that could cause a KeyMaterial to be deleted before the file that it encrypts

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