Avoid Deepcopy on Tree and ParticleTree

[fjloyola]

To avoid deepcopy we have to change some constructors and implement method copy, here is the list of all the changes:

• Implement a constructor of Tree with all the attributes(tree_structure, idx_leaf_nodes and output);
• Create the class method new_tree with the previous behavior of the constructor;
• Change the implementation of copy on Tree, avoiding deepcopying all and just deepcopying the output;
• Improve method trim(), previously we copy all and then we delete the attributes that we do not need, now we just create the tree copying the attributes that we care;
• Instead of creating an empty list and append each particle we create an comprehensive list; We implement the method copy on ParticleTree, instead of deepcopying;

Tested Mac with chip M1, 8 cores and 16 gb of ram having the next results:

Configuration			version performances		improvements
model name	tree º	particle º	current	new	%
biking	50	20	85 sec	74 sec	12,94%
		40	123 sec	99 sec	19,51%
		60	160 sec	128 sec	20,00%
	100	20	115 sec	103 sec	10,43%
		40	207 sec	154 sec	25,60%
		60	262 sec	209 sec	20,23%
	200	20	212 sec	164 sec	22,64%
		40	338 sec	267 sec	21,01%
		60	519 sec	378 sec	27,17%
coal	50	20	67 sec	57 sec	14,93%
		40	92 sec	83 sec	9,78%
		60	124 sec	104 sec	16,13%
	100	20	97 sec	85 sec	12,37%
		40	154 sec	135 sec	12,34%
		60	209 sec	181 sec	13,40%
	200	20	159 sec	138 sec	13,21%
		40	264 sec	229 sec	13,26%
		60	381 sec	319 sec	16,27%
friedman	50	20	78 sec	65 sec	16,67%
		40	120 sec	91 sec	24,17%
		60	171 sec	115 sec	32,75%
	100	20	118 sec	93 sec	21,19%
		40	216 sec	144 sec	33,33%
		60	304 sec	200 sec	34,21%
	200	20	199 sec	150 sec	24,62%
		40	380 sec	246 sec	35,26%
		60	556 sec	354 sec	36,33%
space_influenza	50	20	79 sec	66 sec	16,46%
		40	115 sec	95 sec	17,39%
		60	158 sec	125 sec	20,89%
	100	20	109 sec	101 sec	7,34%
		40	198 sec	153 sec	22,73%
		60	262 sec	207 sec	20,99%
	200	20	178 sec	158 sec	11,24%
		40	310 sec	271 sec	12,58%
		60	444 sec	381 sec	14,19%

[aloctavodia]

LGTM!