Make code blocks easier (eg Python, R, command line, JS, Sikuli)

[kensoh]

Now - to make calls and write code for integrations, the respective steps are used. however, each line needs to be preceded by the step name for TagUI to understand that the line is meant for Python or R or others.

For example, the block below. This may be alright for a few lines, for situations where a large number of lines are needed and loading from a file is not preferred it can be tedious to keep typing the step name in front.

py a=1;b=2
py c=a+b
py print c

There - the structure below makes more sense for longer blocks of integrations code. This issue is raised to track this enhancement. Of course, existing code with each line starting with the integration step name should continue to work.

py begin
a=1;b=2
c=a+b
print c
py finish

[kensoh]

Above commit should make code blocks work for steps py, r, run, vision, js, dom (both normal execution and live mode). Tested for py step, to test remaining steps before closing issue.

[kensoh]

Looks good! Tested for steps py, r, run, vision, js, dom for normal and live mode.