fix: UI tab name and reranking process for TeiFastReranking

[tknrych]

Description

• Please include a summary of the changes and the related issue.
• Fixes # (issue)

Type of change

• New features (non-breaking change).
• Bug fix (non-breaking change).
• Breaking change (fix or feature that would cause existing functionality not to work as expected).

Checklist

• I have performed a self-review of my code.
• I have added thorough tests if it is a core feature.
• There is a reference to the original bug report and related work.
• I have commented on my code, particularly in hard-to-understand areas.
• The feature is well documented.

[tknrych]

When using TeiFastReranking as the reranking method, if a string exceeding the Max Tokens supported by the Reranker Model specified on the TeiFastReranking Server side is passed, the server returns an error. As a result, an error warning would also be displayed on the kotaemon interface. Although the is_truncated option was present in the kotaemon code, no processing was implemented for it. To address this, functionality was added to allow specifying the max_tokens option alongside the is_truncated option. If a string exceeding the specified max_tokens is passed, the string will now be truncated accordingly.

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