invoice: Use PaymentHash in raw invoice types

[jgmcalpine]

Closes #4292

Note: This is a breaking change for InvoiceBuilder. Downstream consumers (like ldk-node) will need to update their builder calls to pass PaymentHash directly.

Refactors RawBolt11Invoice, RawDataPart, and TaggedField to use
lightning_types::payment::PaymentHash instead of bitcoin::hashes::sha256::Hash.
This improves type safety and aligns the raw invoice types with the high-level
Bolt11Invoice.

This is a follow-up to #4293 to complete the migration of invoice types to PaymentHash.

Specific changes:

• TaggedField::PaymentHash now holds a PaymentHash.
• InvoiceBuilder::payment_hash now accepts a PaymentHash directly.
• Implemented Base32 traits for PaymentHash in lightning-invoice to support
  serialization.
• Updated tests to resolve name collisions between the PaymentHash type and
  the TaggedField variant.
• Updated downstream usage in the lightning crate (channelmanager and
  invoice_utils) to remove redundant hash conversions now that the builder
  accepts the strong type.

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[TheBlueMatt]

Huh? Same below.

[jgmcalpine]

Ah, good catch. That was a redundant round-trip left over from when I was refactoring the types. Simplified it to just use invoice.payment_hash() directly

[codecov]

Codecov Report

❌ Patch coverage is 99.37107% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 86.09%. Comparing base (f9ad345) to head (59b1623).
⚠️ Report is 19 commits behind head on main.

Files with missing lines	Patch %	Lines
lightning-invoice/src/de.rs	98.63%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4363   +/-   ##
=======================================
  Coverage   86.09%   86.09%           
=======================================
  Files         156      156           
  Lines      102804   102853   +49     
  Branches   102804   102853   +49     
=======================================
+ Hits        88508    88553   +45     
+ Misses      11788    11784    -4     
- Partials     2508     2516    +8     

Flag	Coverage Δ
tests	86.09% <99.37%> (+<0.01%)	⬆️

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