Enable more compile warnings

and fix the fallout detected.

added 10 commits

• 16e292c3...bd49f03a - 2 commits from branch Librem5:master
• e8d6270e - meson: Move protocol building to protocol/
• 3dfb5bfc - meson: Warn about unused functions
• 6d6a6784 - meson: Warn about old-style function definitions
• 97e8e3d5 - meson: Properly sort in -Wmaybe-uninitialized
• 8c3c378a - meson: Make missing declarations an error
• 8031d2b2 - meson: Enable more warnings
• f9a4a46a - meson: Enable strict prototypes
• a197e597 - meson: enable -Wextra

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added 1 commit

• 0e9bf498 - meson: Enable -Wextra

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added 1 commit

• 5d4adb5b - meson: Forbid implicit fallthrough

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added 3 commits

• e116d14f - meson: Enable more warnings
• 87f24647 - meson: Enable strict prototypes
• 43ac7f6d - meson: Forbid implicit fallthrough

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enabled an automatic merge when the pipeline for 43ac7f6d succeeds

merged

mentioned in commit e2feba0c