…lastic#205138)

**Resolves: elastic#202016

## Summary

This PR resolves an issue where the diff view incorrectly marked certain
characters as changed (using bold font) in some cases.

## Root Cause
The issue arises from a bug in the `diff` library (v5). The library is
used to compute two-way diffs between strings (old field value and new
field value), producing an array of change objects that is then used for
rendering.

Conditions for the bug:
- `diff` v5 library is in use (fixed in v6 and above) and
`DiffMethod.WORDS` is passed as a parameter to it.
- The old field value contains a line with an addition separated by a
space (see example below).
- The next line contains some changes (additions, deletions, or
updates).

For example, for these input strings:
```
foo bar
spring
```
```
foo
sprint
```

| You would expect to see this diff | But you actually see this |
|----------|----------|
| <img width="119" alt="expected"
src="https://github.com/user-attachments/assets/c41b3dec-e578-4a12-8eb8-91fbb60d7247"
/> | <img width="118" alt="actual"
src="https://github.com/user-attachments/assets/f2a33fee-5de2-4291-876a-e7575ea07079"
/> |

**A more real-life example**
<img width="1661" alt="more_real_life"
src="https://github.com/user-attachments/assets/91ebfe93-81ad-45c8-8f9b-e173c2cf940b"
/>

## Solution
Switching to `DiffMethod.WORDS_WITH_SPACE` avoids this issue.
Screenshot showing the difference between `DiffMethod.WORDS` and
`DiffMethod.WORDS_WITH_SPACE`:
<img width="675" alt="words_vs_words_with_space"
src="https://github.com/user-attachments/assets/3c91e1d2-63fc-4fcd-a762-a905878bfc3a"
/>

## Other changes
- Removed `DiffMethod.TRIMMED_LINES` since it's now
[deprecated](kpdecker/jsdiff#486) in the `diff`
library and we are not using it anyways.
- Stopped using the "zip" option since I believe it produces a less
readable diff, especially for cases when there's a different number of
lines in the original value vs updated value.

<details>
<summary><strong>Screenshots: with and without "zip" (click to
expand)</strong></summary>
<strong>With the "zip" option (how it was before)</strong>
<img width="1918" alt="zip"
src="https://github.com/user-attachments/assets/272ed849-47d6-4fef-8acc-ab1b22c9f42e"
/>

<strong>No "zip" (this branch)</strong>
<img width="1919" alt="no_zip"
src="https://github.com/user-attachments/assets/417303bf-9570-4ee1-98c5-8a78f59c7956"
/>
</details>

## Testing

I thoroughly tested with `DiffMethod.WORDS_WITH_SPACE` across various
inputs and scenarios, including:
- Single-line and multi-line strings.
- Numbers, arrays, and objects.
- Additions, deletions, and updates at different positions (start,
middle, and end) within and across lines.

I also validated diffs against real prebuilt rules by installing an
older Fleet package version and observed no issues.

You can test by trying different input strings and settings in
Storybook.
**Run Storybook**: `yarn storybook security_solution`.

https://github.com/user-attachments/assets/0440b73c-a4d7-40cf-9cee-e632146d292e

You can notice that `ComparisonSide` stories are broken, but that's
unrelated to these changes and needs to be handled separately.

## Compatibility with future upgrades

There's an open [PR](elastic#202622) that
will upgrade the `diff` library from v5 to v7. I verified the behavior
of `DiffMethod.WORDS_WITH_SPACE` on v7 and found no differences compared
to v5, so it should be safe to upgrade to v7 without any changes on our
end.

Work started on 23-Dec-2024.

(cherry picked from commit 140c2e0)

# Conflicts:
#	x-pack/plugins/security_solution/public/detection_engine/rule_management/components/rule_details/json_diff/diff_view.stories.tsx