Implement bench backrest quest

[Map3428]

Fix #484

A neat icon is still missing, I can't design it.

[ENT8R]

A neat icon is still missing, I can't design it.

I can try to create one.

[westnordost]

Why do you think that picnic tables are often (enough) mistagged as benches to warrant a specific handling for that?
(After all, there is always the leave-a-note option)

[matkoniecz]

Also, what about cases where both picnic table and bench are mapped? User may mistakenly retag benches to tables.

BTW, is there any, even potential use for this data?

[westnordost]

Perhaps useful information for the physically impaired / old people? @rugk seemed to be enthusiastic about this quest.

[westnordost]

(Is missing an icon. Suggestion: A walking cane.)

[rugk]

So as for the use case, it may not only be for visually impared people. I still remember that OsmAnd may display difficult icons or so. 😄

Also there is even a map for that: https://www.mapcontrib.xyz/t/4da70b-Bancs_et_tables_de_pique_nique#

Also, what about cases where both picnic table and bench are mapped?

AFAIK this is not a valid mapping is it? Otherwise one may just need to remove the picnic option?

(Is missing an icon. Suggestion: A walking cane.)

No, please not. Not only can this potentially be confused with tactile paving quests and similar, but it does also not really indicate that this is about a bench.
It is way easier: Just use a bench as an icon for that. AFAIK there is not a other quest, which may be asked about benches, so the icon would not even be used twice, potentially. (and even if it would, that is not so bad, as it the icon is used in the toilets quests or so twice)

[westnordost]

I added a bench icon to the repository 🎉

[rugk]

*have

[westnordost]

Okay I did this now. Congrats for your first quest, @Map3428 :-)