Parser. Long string doesn't contain leading spaces

Nobody has claimed this yet.

### How are you using the lua-language-server?

Visual Studio Code Extension (sumneko.lua)

### Which OS are you using?

Windows

### What is the issue affecting?

Diagnostics/Syntax Checking

### Expected Behaviour

```lua
local a = " sss "
print('"' .. a .. '"')
local a = [[ sss ]] -- bug with a leading spaces
print('"' .. a .. '"')

local a = [[sss]]
print('"' .. a .. '"')
local a = [[
sss]]
print('"' .. a .. '"')
local a = [[
sss]] -- bug with a leading space
print('"' .. a .. '"')

local a = [[sss
]]
print('"' .. a .. '"')
local a = [[
sss
]]
print('"' .. a .. '"')
local a = [[
sss
]] -- bug with a leading space
print('"' .. a .. '"')
```

Parser should produce strings according to Lua rules - in a long string only the first line break is removed, but if it is the first

```
" sss "
" sss "
"sss"
"sss"
"
sss"
"sss
"
"sss
"
"
sss
"
```

### Actual Behaviour

The leading spaces were skipped, presumably due to the fact that these are not tokens. Or I don't know

https://github.com/LuaLS/lua-language-server/blob/cb964c600570e6258d3c0a3f3f424a35a3a4ef64/script/parser/compile.lua#L429-L430

https://github.com/LuaLS/lua-language-server/blob/cb964c600570e6258d3c0a3f3f424a35a3a4ef64/script/parser/compile.lua#L381-L394


### Reproduction steps

1. Try to parse long string `[[ sss ]]`
2. Now its `[[sss ]]`

### Additional Notes

This also breaks the colorization in addition to #3032, most likely because it breaks the start/finish positions #3028

```lua
--[===[@param a string?ComMMul]===]
local function new(a) end

--[===[ @param a string?ComMMS1]===]
local function new(a) end
```


### Log File

_No response_

Start with script/parser/compile.lua at the referenced lines 381-394 and 429-430, then reproduce the listed long-string cases. Compare parsed values and source ranges with the expected Lua outputs, including leading spaces and line breaks. Done means leading spaces are preserved and the affected colorization and start/finish positions no longer regress.

Written by the indexing model from the issue text.