Implement access to accented characters

Implement a strategy to enable switch access (including all scanning modalities) to accented characters

Jan proposed the following idea:

There is a new setting called "Enable accent scanning" (or similar)
 - when OFF, everything works as it does now
 - when ON (see below)

Accent Scanning
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When the user selects a letter from the alphanumeric keyboard that has accent variants the variants come up in a new keyboard with the unaccented variant first (so a quick double click will select that).

Once a variant is selected, the regular alphanumeric keyboard returns.