Issues with event function definition

When trying to create an event rpc function I ran into several type issue.
```
---@enum EventAudienceEnum
EventAudienceEnum = {
ALL = "ALL",
ALL_BUT_SELF = "ALL_BUT_SELF",
SELF = "SELF",
SELECT = "SELECT",
SERVER = "SERVER",
OWNER = "OWNER",
}

---@class EventAudienceSelect
---@field [0] EventAudienceEnum.SELECT
---@field peer_ids string | string[]

---@class EventAudienceOwner
---@field [0] EventAudienceEnum.OWNER
---@field unit string

---@alias EventAudience
---| EventAudienceEnum.ALL # comment
---| EventAudienceEnum.ALL_BUT_SELF # comment
---| EventAudienceEnum.SELF # comment
---| EventAudienceEnum.SERVER # comment
---| EventAudienceSelect # comment
---| EventAudienceOwner # comment

--- Send event
---@param audience EventAudience who to send the event to
---@param event string event to call
---@param ... any params to pass to the event
function Events.send_event(audience, event, ...)
end
```

Issue 1: Can't use specific enums as types (https://github.com/LuaLS/lua-language-server/issues/2274)
Issue 2: You do not get the missing field diagnostic on 'dictionary', or 'table-literal' types
Ex:
```
---@param audience { [0]: "SELECT", ["peer_ids"]: string | string[] } who to send event to
---@param event string event to call
---@param ... any params to pass to the event
function Events.send_event(audience, event, ...)
end

Events.send_event({
}, "test", "test")
```
and
```
---@param audience { [0]: "SELECT", peer_ids: string | string[] } who to send event to
---@param event string event to call
---@param ... any params to pass to the event
function Events.send_event(audience, event, ...)
end

Events.send_event({
}, "test", "test")
```
gives no errors

Issue 3: Alias comments only show stuff for strings or numbers

I would have expected the alias comment here to also say
```
| EventAudienceSelect
| EventAudienceOwner
```

Issue 4: There is no missing-param diagnostic for 'number' fields:
```
Events.send_event({peer_ids = {}}, "test", "test")
```
I would have expected an error here:

but none is given

Issue 5: There is no type-checking on 'number' fields of classes, unless you explicitly call out the number. For example there is no error here:

even though there is an error here:

Issue 6: There are issues with the missing field diagnostic and unions. For example I get an error that I need to define peer_ids here:

when I would expect it to work as EventAudienceOwener has no peer_ids. I expect this is related to https://github.com/LuaLS/lua-language-server/issues/2252 (and https://github.com/LuaLS/lua-language-server/issues/2102)

Until unions are properly implemented, it would nice to be able to disable the missing-field-diagnostic at the table level instead of at the usage level. (Something like suggested here: https://github.com/LuaLS/lua-language-server/issues/2220)

Sorry this was a little long, let me know if you want me to seperate this out into seperate issues 👍

Start by reproducing the six type-checking and diagnostic examples in issue #2279, then compare the behavior with related issues #2274, #2252, #2102, and #2220. Done would require a clarified scope and verified behavior for the selected enum, missing-field, alias-comment, numeric-field, and union cases.

Written by the indexing model from the issue text.