Combine get_effort() and get_custom_effort() into new function effort()

[peterdesmet]

Suggested in camtraptor July 2023 coding sprint

get_effort() returns effort information per deployment:

library(camtraptor)
get_effort(mica)
#> # A tibble: 4 × 4
#>   deploymentID                         effort unit  effort_duration       
#>   <chr>                                 <dbl> <chr> <Duration>            
#> 1 29b7d356-4bb4-4ec4-b792-2af5cc32efa8   239. hour  859859s (~1.42 weeks) 
#> 2 577b543a-2cf1-4b23-b6d2-cda7e2eac372   219. hour  786802s (~1.3 weeks)  
#> 3 62c200a9-0e03-4495-bcd8-032944f6f5a1   529. hour  1903602s (~3.15 weeks)
#> 4 7ca633fa-64f8-4cfc-a628-6b0c419056d7   335. hour  1204929s (~1.99 weeks)

get_custom_effort() returns effort information (for the entire project), per group_by unit:

``` r
library(camtraptor)
get_custom_effort(
  mica,
  group_by = "year"
)
#> # A tibble: 2 × 3
#>   begin      effort unit 
#>   <date>      <dbl> <chr>
#> 1 2019-10-09   792. hour 
#> 2 2020-10-08   529. hour

We think it would be better to combine this in one function, where deploymentID is one of the group_by variables to replicate the behaviour of get_effort:

get_custom_effort(
  package = NULL,
  # ... removed, see filters
  # start = NULL removed, see filters
  # end = NULL removed, see filters
  group_by = NULL, # options are "deploymentID", "day", "week", "month", "year"
  unit = "hour", # options are "hour", "day" (unchanged)
  # datapkg removed
)

The returned information would be:

deploymentID, day, week, month or year # not "begin", preferably column has the group_by property
effort
unit
effort_duration # exist in get_effort, not get_custom_effort, but can likely be returned for both

[jimcasaer]

see issue #219 -- can this be integrated / changed when creating this new function effort ?