feat: add CDSL Consolidated Account Statement support

[ratankumarorg-source]

Summary

• Adds full CDSL (Central Depository Services) CAS PDF parsing support
• Previously casparser only supported NSDL demat CAS statements; CDSL files crashed with "Error parsing CAS header"

Changes

New file: casparser/process/cdsl_statement.py

Complete CDSL CAS parser that extracts:

• Demat holdings: equities, mutual funds held in demat form, and bonds
• Mutual fund folio holdings: scheme name, ISIN, closing units, NAV, valuation
• Handles multi-line security names, page breaks within holding sections, and Indian number formatting

Modified: casparser/process/__init__.py

• Route FileType.CDSL to the new process_cdsl_text parser

Modified: casparser/process/nsdl_statement.py

• Fix parse_header to search the full extracted text instead of just text[:1000] (the properly formatted date on some CAS statements falls beyond the first 1000 characters)

Modified: casparser/cli.py

• Fix formatINR to consistently produce 2 decimal places (previously dropped trailing zeros e.g. ₹1,00,390.0 → now ₹1,00,390.00)
• Add asset class breakdown summary in print_nsdl showing Debts, Equities (demat), Mutual Funds (demat), Mutual Fund Folios totals
• Improve table column sizing (max_width/overflow on Name column, fixed ISIN column width) to prevent content truncation

Testing

Successfully parsed a 21-page CDSL CAS PDF containing:

• 2 demat accounts (28 equities + 11 MFs in demat + 1 bond)
• 7 mutual fund folios
• Total portfolio value: ₹1,64,79,242.07

All existing parsers (CAMS, Kfintech, NSDL) remain unchanged.

[codereverser]

Many thanks for the PR. It was a long-standing feature request.

I noticed that it breaks for one CDSL CAS statement I have (works on others), but the issue is with the parser, not the code here. I'll try to fix it in a separate PR.