Fix: ensure manager entries load even if preceding ones failed

[ndelangen]

Issue: #20285

What I did

I changed the generated code loading managerEntries so there's error handling

[ndelangen]

So this doesn't work because of a race-condition between the manager self-executing and managerEntries self-injecting themselves into the manager runtime.

If the managerEntires inject themselves too late, the manager won't pick them up, meaning the addons are missing.
This race-condition might actually already kinda exist, so something that might be happening now, but by making the import imperative, it's now guaranteed that the manager has already fully mounted and called provider.getElements.

It will only do this once, and so: inject too late, and it will never ever show up.

I need to look into how to fix this, but it might require a drastic change in the manager-api. (allowing panels to be added async, after mounting)

storybook/code/lib/manager-api/src/modules/addons.ts

Line 40 in 8e4e29c

getElements: (type) => provider.getElements(type),

[ndelangen]

It all being async would also make it difficult to preserve the order of addons being injected.

[ndelangen]

OK, different approach!

I add a try { <<code >> } catch (e) { .. } around each managerEntry inside of esbuild.

[ndelangen]

@shilman self-merging for release