Migrate to Actix 0.13 APIs, Tokio 1.x, and fix OGN device DB download

[mologie]

(Please do not merge yet, this needs an update to Cargo.toml again after actix-ogn is released.)

I observed ogn-web-gateway on FVA's servers to spend >95% of its CPU time under load in Tokio, Actix, and the kernel [1]. CPU usage then remained at 7 full cores in the late evening, and restarting the service made it return to normal.

This PR replaces the 4+y old dependencies with recent ones just to rule out subtle bugs with recent Linux versions.

The issue may have started after FVA migrated to LXC for containerizing Linux (previously VMware ESXi), which updated the OGN VM's Linux kernel from 4.19 to 5.15 without changing userspace. It may also have been there forever already. We cannot really roll the whole thing back to check again on a busy day.

This depends on Turbo87/actix-ogn#32 being merged and released. Currently Cargo.toml points to ../actix-ogn for the on-master version.

Change summary:

• Raises OGN device DB size limit from 4 MiB to 32 MiB; the server ships a >4 MiB file today.
• No longer depends on OpenSSL
• Uses Actix 0.13 and Actix-Web 4
• Updated Sentry integration for compatibility and for removing OpenSSL, but I cannot it without personal account. Would appreciate if you could give this one a shot with your existing setup.

Tests done:

• cargo test passes
• Checked that echo 'bbox|-1.163826432568077|49.131099997360025|14.656486067431924|52.2073178286237' | websocat -n1 ws:https://localhost:9999/api/live still returns data
• Checked that API status endpoint's positions counter increases after starting with an empty local redis database
• I did not actually connect the ogn-web-viewer to this; npm install fails for me because it attempts to access phantomjs, which is not available for my platform (Apple M1), did not investigate this further.
• Testing I did was without SENTRY_DSN set.

I did not update:

• The Redis client. It is unmaintained and the compiler warns that future rust version cannot compile it.
• clap command line parser, API changed and current version does its job.

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[1] perf report when ogn-web-gateway was under load: