[FEATURE] Avoid recomputing values when chaining `LambdaColumn` in one DataPanel

[Sabri Eyuboglu]

If a single DataPanel contains a chain of LambdaColumns, like so

dp["a_b"] = LambdaColumn(dp["a"], fn)
dp["a_b_c"] = LambdaColumn(dp["a_b"], fn_2)

then indexing the DataPanel with dp[0] will perform the materialization of dp["a_b"] twice.

Ideally, the DataPanel should be aware of these dependencies and only materialize things once.

[Sabri Eyuboglu]

In the same vein, we should support linked LambdaColumns where two columns are both products of the same operation .

A use case of this comes up in #222, where an audio loader returns both the time series and the sample rate, which should be in separate columns