[BLE] enable use of local APDU buffer

[yhql]

Description

This PR primarily submits changes to match its use in the Rust SDK.

• The use of HAVE_LOCAL_APDU_BUFFER means G_io_apdu_buffer does not exist anymore and a way to know where to copy received commands is put in place. An additional pointer is added to the main BLE context, and all copies to the global apdu buffer are replaced with copies to this new pointer.
  Its value and associated length can be set externally through a new function. The use of G_io_seproxyhal_spi_buffer is also replaced with locals where possible to ease tracking data moves.

• To make sure bindings to the C APIs are correct, the use of const was enforced were necessary, sometimes requiring modifying the code a bit (see the DEF1 channel ID copy that was moved).

• Functions that enable BLE pairing while in an app were gated so that they can be deactivated, which allows not having to link in snprintf and other functions from another module (ux)

Changes include

• Bugfix (non-breaking change that solves an issue)

[yhql]

Tested as applied on API_LEVEL_5 on a Nano X 2.2.2, on rust-app ("menu" and a "sign" command), and on the current app-boilerplate with a "get name and version" command.

[sportron-ledger]

Hello,
What is the purpose of the HAVE_INAPP_BLE_PAIRING define?

[yhql]

@sportron-ledger it allows disabling parts of the code that require specific dependencies on printf and ux machinery that is not present (or not easy to integrate) in the Rust SDK.

[codecov-commenter]

Codecov Report

Patch and project coverage have no change.

Comparison is base (80b72e7) 69.33% compared to head (2a8c8c6) 69.33%.
Report is 3 commits behind head on master.

Additional details and impacted files

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  Coverage   69.33%   69.33%           
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  Hits          606      606           
  Misses        268      268           

Flag	Coverage Δ
unittests	69.33% <ø> (ø)

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