Fixed bugs in PICSA Rainfall Dialogue

[derekagorhom]

Fixes (partially) #7534
This PR fixes the bugs recently found on the PICSA rainfall graph dialogue.
@N-thony @Vitalis95 can you test.

There seems to be an issue with the dialogue.

1. In the Single variable; when using either Line or Point Options the user has to automatically select the variable it wants to use as the Y variable. (I tried correcting that but it created more problems that solutions).
   to show proof:
   When using the dialogue without Line/Point options:
   ghana <- data_book$get_data_frame(data_name="ghana")
   last_graph <- ggplot2::ggplot(data=ghana,mapping=ggplot2::aes(y=as.numeric(x=rainfall), x=month_abbr))+....

When using the Dialogue with Line/Point options:
ghana <- data_book$get_data_frame(data_name="ghana")
last_graph <- ggplot2::ggplot(data=ghana, mapping=ggplot2::aes(y=rainfall, x=month_abbr)) +...

And finally when using the dialogue with the multiple variable:
ghana <- data_book$get_data_frame(data_name="ghana", stack_data=TRUE, measure.vars=c("min_temperature","max_temperature"))
last_graph <- ggplot2::ggplot(data=ghana, mapping=ggplot2::aes(y=as.numeric(x=value), colour=variable, x=month_abbr)) +....

This PR does not fix issue #7534...but rather the bugs reported by Antoine and Vitalis

[rdstern]

Please can @Vitalis95 and @N-thony check and report on this fix. I can't find the corresponding issues from them, so I'll wait for their evaluation.

[N-thony]

This PR fixes the bugs recently found on the PICSA rainfall graph dialogue. @N-thony @Vitalis95 can you test.

There seems to be an issue with the dialogue.

1. In the Single variable; when using either Line or Point Options the user has to automatically select the variable it wants to use as the Y variable. (I tried correcting that but it created more problems that solutions).
   to show proof:
   When using the dialogue without Line/Point options:
   ghana <- data_book$get_data_frame(data_name="ghana")
   last_graph <- ggplot2::ggplot(data=ghana,mapping=ggplot2::aes(y=as.numeric(x=rainfall), x=month_abbr))+....

When using the Dialogue with Line/Point options: ghana <- data_book$get_data_frame(data_name="ghana") last_graph <- ggplot2::ggplot(data=ghana, mapping=ggplot2::aes(y=rainfall, x=month_abbr)) +...

And finally when using the dialogue with the multiple variable: ghana <- data_book$get_data_frame(data_name="ghana", stack_data=TRUE, measure.vars=c("min_temperature","max_temperature")) last_graph <- ggplot2::ggplot(data=ghana, mapping=ggplot2::aes(y=as.numeric(x=value), colour=variable, x=month_abbr)) +....

This PR does not fix issue #7534...but rather the bugs reported by Antoine and Vitalis

@derekagorhom I thought this will be done in the same PR i.e #7534 since it concerns the dialogue you are working on there.

[derekagorhom]

Yes but since @Vitalis95 was working on the same dialogue, i wanted to be done this bug and continue with #7534

[Vitalis95]

@rdstern , the bugs I found after pulling the changes made on PR #7505 and those bugs I raised them in the issue #7534 and are now solved.
those bugs were -
i) the argument 'x' was missing
ii) when you go back to the dialog, the variable in the single receiver you had added was not there again and when you add it back , the test OK now was disabled
Also the bug @N-thony raised where, When you click on multiple receive, the single receiver is still present is also sorted

[N-thony]

@rdstern , the bugs I found after pulling the changes made on PR #7505 and those bugs I raised them in the issue #7534 and are now solved. those bugs were - i) the argument 'x' was missing ii) when you go back to the dialog, the variable in the single receiver you had added was not there again and when you add it back , the test OK now was disabled Also the bug @N-thony raised where, When you click on multiple receive, the single receiver is still present is also sorted

@rdstern could you also test?

[rdstern]

It seems to work fine, except for the bug I found, which I gather will be fixed separately. So happy to approve. It will be good, so that @Vitalis95 can work on other aspects of this dialogue.