feat: strip markdown in messages table

[kantord]

fixes #321

Before

After

Explanation

In order to fix visual issues there, I decided to simply strip markdown (=convert .md to .txt) in the table. While there could be alternative solutions, such as only stripping problematic things from the prompt and displaying the rest, I think

• it would not help the users much
• could even be a performance issue
• lot of code to maintain
• perhaps we won't even keep this column, or we will display an ai generate summary or similar

For the implementation I used remark and a remark plugin, because we already indirectly depend on remark, so this way the added dependencies should be minimized.

[stacklok-cloud-staging]

Minder Vulnerability Report ✅

Minder analyzed this PR and found it does not add any new vulnerable dependencies.

Vulnerability scan of c228e332:

• 🐞 vulnerable packages: 0
• 🛠 fixes available for: 0

[coveralls]

Pull Request Test Coverage Report for Build 13410965963

Details

• 2 of 2 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.03%) to 69.945%

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Totals
Change from base Build 13410704822:	0.03%
Covered Lines:	847
Relevant Lines:	1153

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💛 - Coveralls