Respect original content when creating secrets

[wolfogre]

Fix #24721.

Follow what GitHub does:

• Don't trim spaces for secrets.
• Newline should be \n instead of \r\n.

Did some tests with:

name: secrets
on: push
jobs:
  show_secrets:
    runs-on: ubuntu-latest
    steps:
      - name: Dump secrets context
        run: echo '${{ toJSON(secrets) }}' | base64

AAAAAA:

   AAAAAA
AAAAAA

BBBBBB:

BBBBBB
BBBBBB   

On GitHub:

On Gitea (before):

On Gitea (after):

[wolfogre]

Need help:

The newline in textarea is \r\n, how to change it to \n (like GitHub)?

---

Update:

Since it's a standard behavior of HTML, I'll repleace \r\n at backend.

[wxiaoguang]

The newline in textarea is \r\n, how to change it to \n?

There is a standard.

https://html.spec.whatwg.org/multipage/forms.html#the-textarea-element

For historical reasons, the element's value is normalized in three different ways for three different purposes.
The raw value is the value as it was originally set. It is not normalized.
The API value ... It is normalized so that line breaks use U+000A LINE FEED (LF) characters.

[wxiaoguang]

And this:

https://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.3.2

Control names and values are escaped. Space characters are replaced by '+', and then reserved characters are escaped as described in [RFC1738], section 2.2: Non-alphanumeric characters are replaced by '%HH', a percent sign and two hexadecimal digits representing the ASCII code of the character. Line breaks are represented as "CR LF" pairs (i.e., '%0D%0A').

[delvh]

Hmm… I don't know why this PR was merged, and why it is necessary in the first place.
I mean, I think it's a much better user experience that trailing spaces are cut as they can appear when copying a secret.
On the other hand, secrets with trailing spaces are such an uncommon case that I don't think we should support them.

So, for me, the logical choice would be to restore the previous behavior to avoid user complaints.
This depends of course if we want secrets to be

1. usable for everyone but not user-friendly
   or
2. easily usable for 99% of developers.

I'm in favor of option 2.

[delvh]

Oh, by the way, this PR was certainly not a bug but expected behavior. So, if at all it's an enhancement, although I'd still doubt that (see above).
I think I even commented something of the form

I like that we trim trailing whitespace around Secrets unlike GitHub

on the original secrets PR.

[silverwind]

I generall prefer to trim all input fields as well, it's such a common user error that I think it warrants it. In case a user really wants untrimmed values, a option could be added to the user settings to disable the trimming.