Added Trend keyboard and general changes to layout for the Hypothesis Tests dialog

[Wycklife]

Fixes #5816 and #5814

@africanmathsinitiative/developers This is ready for review

[rdstern]

@wyclife - this is looking good.
a) On the keys from the third row there is ::: (i.e. 3 colons) rather than just 2. In the bottom row it rises to ::::.
b) the tooltip for mk has Trend Test, rather than trend test. (All the other seem consistent - great.)
c) Put the Clear button before (and on the left, next to the Help), rather than underneath it.
d) Move the Try control slightly left, so it is aligned with the check boxes above and then it can also move upwards so it is next to the bottom row of the symbol keys. Move the other keys at the left so they all align and also so that the dialogue becomes less deep.
e) Finally something new that I need to check with @dannyparsons. In some commands we need to include the data frame name in the command. Currently this can't be done, i.e. you can't click and Add the data-frame name. If this is easy it would be useful to add - otherwise it should not holdup the merging, but can become a new issue.

[Wycklife]

@rdstern I have fixed the first 4 points above. @africanmathsinitiative/developers Could someone have a look at these changes.

[rdstern]

@Wycklife you have fixed the first 3 - here is the 4th

d) Move the Try control slightly left, so it is aligned with the check boxes above (if aligned now, then move them all a bit left) and then it can also move upwards so it is next to the bottom row of the symbol keys. Move the other keys at the left so they all align and also so that the dialogue becomes less deep.

Ignore the final point (e) above for now. I have discussed with @dannyparsons and will make a separate issue.

[Wycklife]

@rdstern Done. Kindly check a gain.

[rdstern]

@Wycklife , that is a bit better but not quite right yet. We have just started adding @lilyclements back into the team and re-organising dialogues is one of her strengths. So I suggest it remains as your pull request, but she will do some edits of the layout. She is likely to have more ideas than those I gave you! Let's see.

[Wycklife]

@rdstern That's fine.

[lilyclements]

@Wycklife would you mind updating this branch from the master copy?

[Wycklife]

@rdstern I have merged the changes made by @lilyclements into this branch. Could you please check if the designer is now okay.

[rdstern]

I am happy to approve. I am commenting so @lloyddewit can check and hopefully approve.

[lloyddewit]

@maxwellfundi I reviewed, it looks good and I''m happy to approve. Please merge, thanks

[lloyddewit]

@rdstern You already approved this. Please could you approve again so that we can merge? thanks

[lloyddewit]

@rdstern You already approved this. Please could you approve again so that we can merge? thanks

[rdstern]

Happy to approve again