Show content in files by default

[ea-rus]

Changes:

• Show content in files table by default
• default limit is 10

It will enable to use simple join with model which uses content:

SELECT t.name, t.content, m.question
   FROM my_github.files t
    JOIN question_generator as m
where t.path = 'mindsdb/integrations/handlers' 
LIMIT 1 

instead of

 SELECT t.name, t.content, m.question
    FROM (
        select name, content from my_github.files
        where path = 'mindsdb/integrations/handlers' 
        LIMIT 1 
        ) as t
    JOIN question_generator as m  

Description

Please include a summary of the change and the issue it solves.

Fixes #issue_number

Type of change

• ⚡ New feature (non-breaking change which adds functionality)

Verification Process

To ensure the changes are working as expected:

• Test Location: Specify the URL or path for testing.
• Verification Steps: Outline the steps or queries needed to validate the change. Include any data, configurations, or actions required to reproduce or see the new functionality.

Additional Media:

• I have attached a brief loom video or screenshots showcasing the new functionality or change.

Checklist:

• My code follows the style guidelines(PEP 8) of MindsDB.
• I have appropriately commented on my code, especially in complex areas.
• Necessary documentation updates are either made or tracked in issues.
• Relevant unit and integration tests are updated or added.

[paxcema]

LGTM