[improve][doc] Improve the information architecture of the security chapter

[momo-jun]

Motivation

Improve the doc set of the Security chapter to provide Pulsar users with a more accurate, easy-to-read, and comprehensive information experience.

Note: This PR is a quick change to the overall IA of security topics. I will include more detailed IA changes and content changes for encryption and authentication in a couple of follow-up PRs, such as #17666.

Modifications

1. Group encryption- and authentication-related topics in the sidebar (titles of some topics can be improved later).

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2. Move TLS encryption/authentication using Keystore sections to related parent topics, and remove Use TLS with KeyStore topic.
3. Streamline the headings of authentication topics.
4. Use language tabs to group code snippets throughout the security chapter.
5. Remove the java code snippets from the java client page, and add links to individual authentication topics - fix [Doc] Authentication documentation mismatch / outdated #17561.
6. Add code snippet for python clients to support basic auth [feat][python] Add basic authentication #17482.
7. Add code snippet for go clients to support basic auth feat: add basic authentication pulsar-client-go#778.

Preview looks good. I've checked all the topics and here is one of the screenshots.

Documentation

• doc

[nodece]

Overall looks good to me.

[Anonymitaet]

1. ### instead of ####?

2. Other headings are in the format of "Verb + xxx" while this heading is not.

Consider keeping consistent or turning this section into other content formats (like moving lines 97 - 100 to line 74)?

So that users know the relationship between the section Configure Athenz authentication in Pulsar clients and Supported pattern formats

(the info in Supported pattern format can be a part of Configure Athenz authentication in Pulsar clients )

[momo-jun]

It's copied and pasted here from another topic. I guess the intention was kind of to be a reference sub-topic so that's why #### was used (not shown in the hot links). Thanks for the reminder. It will be evaluated in a further review throughout the topic.

[momo-jun]

@nodece thanks for the review. Your comments have been addressed.

[nodece]

LGTM

[momo-jun]

@DaveDuggins This is the improvement I mentioned on this Wednesday. Feel free to take a look and comment.