Ability to "Interleave" or "insert" cubes

[acchamber]

✨ Feature Request

I often encounter situations where I am constructing a cube from smaller cubes (such as hourly .nc files). When I do so sometimes I find there's missing values (common in observational data) that I want to infill. However, you cannot concatenate data into the middle of a cube, even if it doesn't overlap. For example:

I have a cube main with the following dim_coord

[0,1,2,3...7799,7800]

But there's missing values at [56] and [3567]. The cube just goes [... 55, 57 ...] and [... 3566, 3568 ... ].

I have cubes with the [56] and [3567] coord that I want to insert into the cube but I cannot

the current workaround is to define new cubes of main[:55],main[56:], then concatenate the cubelist of the three( main[:55],main[56:], [56]) , but this approach is brittle and does not scale well (when you have a 100 missing values this scales poorly)

Ideally, the solution would also allow for more complex interleaving - eg

cube A [0,3,6,9,12] Cube B [1,2,4,5,7,8,10,11]

cube c = interleave([Cube A, Cube b])

Additional context

This would only need to function in one dimension - obviously all other dimensions would have to match. Discussed with @bjlittle at surgery.