bug: missing abstract length validation (<= 200 chars) and incomplete Databus URI validation

[yush-1018]

Bug Report

Describe the bug

1. The CLI help text and function docstring for deploy specify that the abstract parameter must be at most 200 characters long (max 200 chars). However, create_dataset() in databusclient/api/deploy.py does not validate this limit before constructing and sending the dataset payload.
2. Databus URI validation for version_id currently relies on simple string splitting (rsplit('/', 4)), which fails to detect missing URL schemes (http/https), empty path segments, or invalid characters early on the client side.

To Reproduce
Steps to reproduce the behavior:

1. Run the deploy CLI command passing an abstract longer than 200 characters:

   databusclient deploy \
     --version-id "https://databus.dbpedia.org/user/group/artifact/1.0.0" \
     --title "Sample Title" \
     --abstract "$(python3 -c 'print("A"*210)')" \
     --description "Sample Description" \
     --license "https://dalicc.net/licenses/cc-by-4.0" \
     --apikey "dummy_key" \
     https://example.com/data.ttl
   

Expected behavior

1. The client should validate len(artifact_version_abstract.strip()) <= 200 locally in create_dataset() and cli.py, raising a BadArgumentException if the limit is exceeded.
2. The client should validate version_id against a proper URL/URI format before constructing dataset metadata.

Additional context (optional)

• Affected file: databusclient/api/deploy.py (lines 311-365) and databusclient/cli.py.
• Adding unit tests for abstract length enforcement in tests/test_deploy.py will prevent future regressions.

[gitanshhub]

i like to work on this, can you assign this to me