feat: Add metadata filter

[rlinlen]

Issue #, if available:
#621
As an admin, when creating a bot I would like to limit the users to search only the relevant data in KB based on the metadata.

Description of changes:

• Add a component FilterBuilder for UI metadata filter creation
• Modify the component to Bot edit page
• Modify the backend logic to add the metadata filter config under bot.bedrock_knowledge_base. No filter will be used if it's empty.

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