Fixes #79982

Fixes #76941

Fixes #79242

As discussed, renames `toWebviewResource` to `asWebviewUri` to be consistent with the `asAbsolutePath` api naming

Related to #78817

This reverts commit c467419e.

Fix #77813

These values should not be modified

Providers should never mutate this array

Fixes #76077

This change also update our standard link hovers to follow this format

This iteration, we marked a few other arrays as readonly. We should do the same for extensions.all

See #75278

Fixes #74336

This function does not modify the input array

Event data should generally not be mutate as any mutations can leak to other listeners. This change marks most event type members as readonly

Fixes #75278

## Problem
The diagnostic collection object is set up so that it does not mutate the arrays of diagnostics you pass to it. It also does not expect or allow mutation of diagnostics that it returns.

However it it currently typed using normal arrays. This means that if an extension (such as JS/TS) wishes to use readonly diagnostics intnernally, it cannot do so without casting.

## Proposed Fix
Use `ReadonlyArray` in diagnostic collection. This should be a safe change for the `set` type methods. The changes to `get` and `forEach` have the risk of breaking the typing of some extensions, but `get` already returned a frozen array of diagnostic so trying to mutate the array itself would have resulted in runtime error.