Update masp and ibc txs handling

[grarco]

Based on #267.

• Fixes masp note extraction to point to a single inner tx instead of being duplicated for every tx of a batch
• Fixes handling of shielded masp txs
• Fixes extraction of ibc transfer data
• Adds the conversions to the tally of masp notes
• Caches ibc tokens when extracting the transfer data instead of recomputing them

Minor:

• Makes the masp internal address a constant
• Misc refactors and renaming
• Reduces code duplication

NOTE: ibc nfts transfers are not indexed at the moment

[Fraccaman]

mind pointing this to 1.0.0-maint?